CN106957996B - A kind of preparation method of the cold-reduced sheet of super austenitic stainless steel containing Sn - Google Patents

Abstract

The invention provides a method for preparing a Sn-containing super austenitic stainless steel cold-rolled plate, belonging to the technical field of super austenitic stainless steel. The preparation process is as follows: (1) According to the composition ratio of super austenitic stainless steel, add Sn with a mass fraction of 0.05-0.5%, weigh the raw materials, put them into vacuum induction furnace for smelting step by step to obtain molten steel; (2) high-purity Under the protection of nitrogen, the molten steel is poured into a twin-roll thin strip casting and rolling machine for casting and rolling to obtain the original thin strip of Sn-containing super austenitic stainless steel; Controlling single-pass deformation and total deformation” compound production process to prepare cold-rolled plate products with cast strips. The thin strip prepared by the invention can suppress the central segregation of alloying elements, and the strip-shaped microstructure is not easy to appear in the cold-rolled sheet, and the performance of the cold-rolled sheet is better than that of conventional products.

Description

A kind of preparation method of Sn-containing super austenitic stainless steel cold-rolled sheet

technical field

The invention belongs to the field of super austenitic stainless steel preparation, in particular to a method for preparing a Sn-containing super austenitic stainless steel cold-rolled sheet.

Background technique

Super austenitic stainless steel is widely used in petroleum, chemical, paper, food, pipeline and other industries. High alloying is the most important feature of its composition. The overall content of Cr, Ni, Mo and other alloying elements is as high as about 50%, or even higher. High, high alloying provides a guarantee for its excellent performance, but also greatly increases the production cost and manufacturing difficulty. At present, the manufacture of super austenitic stainless steel mainly has the following problems. First, the alloy elements are expensive, and my country is a country lacking in nickel, molybdenum and chromium, so the source and supply of raw materials are largely controlled by others; Due to the high content of alloying elements, it is difficult to smelt and cast. In traditional production methods, central segregation is inevitable. It consumes time and energy in the subsequent high-temperature homogenization process, and in the process of rolling deformation, it is prone to problems of delamination and cracking. , which greatly increases the manufacturing cost; the third is the high alloy element content, which leads to the increase of deformation resistance and the narrowing of the processing window. From the conventional billet to the final product, the processing route is long, energy consumption and environmental pollution are caused The problem is aggravated; Fourth, the current domestic independent production and manufacturing technology for super austenitic stainless steel products is not yet mature, and relies heavily on imports. The main reason for the above problems is that when the slab is produced by the conventional process, the central segregation leads to the enrichment of Mo and Cr in the central area, while the overall content of alloying elements in the surface layer decreases, but it is the surface layer that plays the role of corrosion resistance in the product itself. Therefore, suppressing the segregation of alloying elements becomes the key to solving the above problems. The idea of replacing elements is often used in the development of steel grades and composition optimization. Current research shows that adding a certain amount of Sn to stainless steel can help increase the corrosion resistance of stainless steel, and the source of Sn is wide and the cost is relatively low. Low. If Sn element and Mo element can play a synergistic effect on the corrosion resistance of super austenitic stainless steel, it can not only improve the overall corrosion resistance of super austenitic stainless steel, but also reduce the addition of Mo element.

Patent CN 102274937A discloses adding Sn element to cast-rolled ferritic stainless steel to form a Sn-enriched area near the surface layer, which can improve corrosion resistance. The types and contents of elements in sensitic stainless steel vary greatly, so the effect of Sn on Mo content and its effect on corrosion resistance cannot be predicted. Patent CN 106244811A discloses a low-cost, high-corrosion-resistant Sn-containing ferritic stainless steel and its manufacturing method. Although it contains 0-1.0% Mo, it is still far from the Mo content in super austenitic stainless steel. It is impossible to make substantive guidance for the effect of Sn addition in super austenitic stainless steel on other alloying elements, microstructure and properties.

Contents of the invention

Aiming at the preparation problems existing in the existing super austenitic stainless steel, the invention provides a method for preparing a Sn-containing super austenitic stainless steel cold-rolled sheet.

A preparation method of a Sn-containing super austenitic stainless steel cold-rolled plate, comprising the following steps:

(1) Smelting: Using super austenitic stainless steel with a mass percentage of Sn of 0.05~0.5% as the basic raw material, heat and dry the weighed raw material at 50~100°C for 120~180min, among which the super austenitic The composition mass percentage of stainless steel is: C ≤ 0.03%, N 0.18 ~ 0.25%, Si ≤ 1.0%, Cu ≤ 1.0%, Mn ≤ 2.0%, Mo 6 ~ 8%, Cr 20 ~ 22%, Ni 23.5 ~ 25.5% , the balance is Fe and unavoidable impurities, of which, P ≤ 0.04%, S ≤ 0.03%, O ≤ 0.005%; the raw materials are classified and put into the vacuum induction melting furnace step by step, at a vacuum degree of 4~5 Pa Smelted in a high vacuum environment to obtain molten steel, wherein N is added in the form of ferrochromium nitride, and Sn, Mn and ferrochromium nitride are added in sequence after other raw materials are completely melted;

(2) Casting: Control the pouring temperature between 1500~1600°C, and under the protection of high-purity nitrogen, pour the smelted molten steel into the molten pool of the twin-roll strip casting machine through the tundish for casting and rolling. With the rotation of the casting roll, the casting strip is gradually formed, and a near-net super austenitic stainless steel thin strip with a thickness of 2.5-4 mm and a width of 110-254 mm is prepared. Rolling force 45~65kN;

(3) Temper rolling: The near-network super austenitic stainless steel strip prepared above is sent to a two-roll temper rolling mill. At this time, the temperature of the strip is between 1050 and 1150°C. The thin strip is subjected to one pass of temper rolling, and the rolling deformation is 12.5%~20%, and the thin strip with a thickness of 2~3.5mm, good plate shape and a certain degree of deformation in the solidified structure is obtained, and then crimped;

(4) Homogenization treatment: the above-mentioned flat-rolled thin strip is subjected to high-temperature homogenization treatment under the protection of high-purity Ar or in a vacuum environment, and then quenched to room temperature. Among them, the temperature of homogenization treatment is 1150~1250℃, and the time is 30~120min;

(5) Pickling: Soak the homogenized thin strip in a specific pickling solution for pickling treatment, then wash and dry it with water and alcohol, and use it as the base material of cold-rolled sheet. Wherein, the volume ratio of the pickling solution is HCl:HF:HNO ₃ :H ₂ O =2:3:15:100;

(6) Preparation of cold-rolled sheet: cold-roll deformation of the strip after pickling, with a reduction of 5.7%-20% in a single pass, a total deformation of 40-85.7%, and a final thickness of 0.5-1.2 mm of super austenitic stainless steel strip cold-rolled plate;

(7) The cold-rolled sheet prepared above was annealed and then quenched to room temperature, and then its mechanical properties and corrosion resistance were tested. Wherein, the annealing treatment temperature is 1000-1100° C., and the treatment time is 5-20 minutes.

After testing, the tensile strength of the cold-rolled stainless steel plate prepared by the present invention is 771-788 MPa, the yield strength is 375-390 MPa, the elongation is 47-49%, and the pitting point is 1.00-1.05 V.

Features and significance of the present invention are:

1. The present invention is based on the composition of super austenitic stainless steel, by adding a certain amount of Sn element, adopting the thin strip continuous casting process in the advanced short process, and preparing the super austenitic stainless steel sheet without center segregation phenomenon. bring. A certain amount of Sn element is added, which plays a synergistic effect with the Mo element in the alloy, improving the corrosion resistance of the original super austenitic stainless steel product, while ensuring its mechanical properties. In addition, under the premise of ensuring the same corrosion resistance, the dosage of Mo element during steelmaking can be reduced, the possibility of segregation and the manufacturing cost of products can be reduced.

2. The present invention proposes the concept of controlled rolling and controlled heat treatment of "one pass smooth rolling + homogenization treatment + control of single pass deformation and total deformation" on the cast strip. During the casting and rolling process, subject to the degree of engagement between the side sealing plate and the casting roll, there are more protrusions and uneven parts on the edge of the casting strip. Smooth rolling can improve the shape of the strip, making the strip head and edges more straight and regular. It is beneficial to crimping and subsequent deep processing; temper rolling can also destroy the solidified structure and introduce a certain amount of distortion and dislocation, thereby providing more channels for the diffusion of alloying elements, accelerating the diffusion and homogenization of alloying elements, and reducing the The temperature of homogenization treatment and the time of homogenization treatment are shortened, the energy consumption is reduced, and the tissue is refined to a certain extent.

3. In the process of preparing thin strip cold-rolled sheets, the present invention avoids the risk of cracking of cold-rolled sheets at the edge or surface due to excessive deformation by reasonably controlling the amount of deformation in a single pass and the total amount of deformation. The yield of thin strip cold-rolled sheet provides experimental data and theoretical support for subsequent research work and industrial production. At the same time, the preparation of cold-rolled plate products from thin strips greatly reduces the amount of compression deformation compared with conventional production processes, and the production process route is short, which greatly reduces production and manufacturing costs.

Description of drawings

Fig. 1 is the Sn-containing super austenitic stainless steel strip prepared by embodiment 1;

Fig. 2 is the Sn-containing super austenitic stainless steel thin strip after temper rolling prepared in embodiment 1, the plate shape is good, no edge and surface cracks;

Fig. 3 is the edge portion and surface cracks that occur in rolling after exceeding the amount of deformation in embodiment 1;

Fig. 4 is the cold-rolled strip of Sn-containing super austenitic stainless steel thin strip prepared in embodiment 1, the plate shape is good, and there are no edge and center cracks;

Fig. 5 is the tensile curve of the Sn-containing super austenitic stainless steel cold-rolled sheet prepared in Example 1, excellent tensile strength and excellent plasticity;

Fig. 6 is the polarization curve of the Sn-containing super austenitic stainless steel cold-rolled sheet prepared in embodiment 1;

Fig. 7 is the microstructure of the Sn-containing super austenitic stainless steel cold-rolled sheet prepared in Example 1 and the conventional cold-rolled sheet, and the banded structure in the thin-strip cold-rolled sheet is significantly reduced.

Detailed ways

The model of the vacuum induction smelting furnace adopted in the present invention is ZG-0.05; The twin-roll thin strip cast-rolling machine that adopts is horizontal type, is equipped with internal cooling type roll, and roll diameter is 500mm, and roll body width is 110 ~ 254 mm; The cold rolling mill used is a straight-pull four-roll reversible cold/warm experimental rolling mill; the hot rolling mill used is a Φ450mm×450mm two-roll reversible experimental hot rolling mill.

Comparative example:

The cold-rolled plate of the super austenitic stainless steel thin strip that adopts traditional process preparation among the present invention is used as comparative example, and main steps are:

According to the mass percentage: C ≤ 0.03%, N 0.2%, Si 0.5%, Cu 0.4%, Mn 1.0%, Mo 6.0%, Cr20%, Ni 24%, the balance is Fe and unavoidable impurities, of which, P ≤ 0.04%, S≤ 0.03%, O≤0.005%; classify the raw materials, put them into the vacuum induction melting furnace step by step, and smelt them in a high vacuum environment with a vacuum degree of 4~5Pa to obtain molten steel. Among them, N is Ferrochromium nitride is added in the form of ferrochromium nitride, Mn and ferrochromium nitride are added sequentially after the rest of the raw materials are completely melted; under the protection of nitrogen, conventional ingots are obtained by casting, and the ingots are heated to 1250°C for 300 minutes and then forged to open the billet. The final cast slab was reheated to 1200°C and held for 120 minutes, and hot rolled on a Φ450mm×450mm two-roller reversible experimental hot rolling mill. The starting temperature was 1180°C and the final rolling temperature was 1050°C to obtain a 5.5mm thick After the hot-rolled sheet is quenched to room temperature; then the hot-rolled sheet is kept at 1200°C for 30 minutes and then quenched to complete the annealing treatment. After pickling to remove the scale, it is cold-rolled on a cold-rolling testing machine to obtain a cold-rolled sheet with a thickness of 0.5~1.2mm . Finally, the cold-rolled sheet is annealed at 1000-1100° C. for 5-20 minutes, and then quenched to room temperature to obtain a cold-rolled sheet of super austenitic stainless steel thin strip prepared by a traditional process.

The specific implementation manner of the invention will be described in further detail below, but the implementation manner of this aspect is not limited thereto.

Example 1

A preparation method of a Sn-containing super austenitic stainless steel cold-rolled plate, comprising the following steps:

(1) Smelting: According to the composition ratio of super austenitic stainless steel, weigh the raw materials, and weigh 0.1% Sn by mass fraction, heat and dry each raw material at 80°C for 140min, among which, the super austenitic stainless steel The composition mass percentage of stainless steel is: C ≤ 0.03%, N 0.2%, Si 0.5%, Cu 0.4%, Mn 1.0%, Mo 6%, Cr 20%, Ni 24%, the balance is Fe and unavoidable impurities, Among them, P ≤ 0.04%, S ≤ 0.03%, O ≤ 0.005%; the raw materials are classified, put into a vacuum induction melting furnace step by step, and smelted in a high vacuum environment with a vacuum degree of 4Pa to obtain molten steel, where N is Add in the form of ferrochromium nitride, Sn, Mn and ferrochromium nitride are added sequentially after the rest of the raw materials are completely melted;

(2) Pouring: Control the pouring temperature at 1580°C, and under the protection of high-purity nitrogen, pour the smelted molten steel through the tundish into the molten pool of the twin-roll strip casting machine for casting and rolling. Rotate, the casting strip is gradually formed, and the thickness is 3mm, the width is 110mm Sn-containing super austenitic stainless steel thin strip, wherein the casting and rolling speed is 45m/min, and the casting and rolling force is 55kN;

(3) Temper rolling: The super austenitic stainless steel thin strip prepared above is sent to a two-roll temper rolling mill. At this time, the temperature of the thin strip is 1120°C. At this temperature, the cast strip is subjected to one pass of temper rolling , the rolling deformation is 16.7%, and a thin strip with a thickness of 2.5mm, good plate shape and a certain degree of deformation of the solidified structure is obtained, and then crimped;

(4) Homogenization treatment: The above-mentioned flat-rolled thin strip is subjected to high-temperature homogenization treatment, and then quenched to room temperature. Among them, the temperature of the homogenization treatment is 1200°C, and the time is 60 minutes;

(5) Pickling: Soak the homogenized thin strip in a specific pickling solution for pickling treatment, then wash and dry it with water and alcohol, and use it as the base material of cold-rolled sheet. Wherein, the volume ratio of the pickling solution is HCl:HF:HNO3:H2O=2:3:15:100;

(6) Preparation of cold-rolled sheet: Cold-rolled and deformed the strip after pickling, with a reduction of about 8% in a single pass and a total deformation of 60%, and finally prepared a super austenite with a thickness of 1.0mm Cold rolled stainless steel strip;

(7) Anneal the cold-rolled sheet prepared above, and then test its mechanical properties and corrosion resistance. Wherein, the annealing process is 1000° C.×15 min.

After testing, the tensile strength of the cold-rolled stainless steel plate prepared by the present invention is 785MPa, the yield strength is 388MPa, the elongation is 48%, and the pitting point is 1.01V.

In addition, the thin strip cold-rolled sheet of the same thickness prepared in the comparative example was subjected to the same annealing treatment as in Example 1, and the mechanical properties and corrosion resistance were measured. The results showed that the tensile strength of the traditional cold-rolled sheet was 735MPa , the yield strength is 365MPa, the elongation is 44%, the pitting point is 0.98 V, the performance of Example 1 is better than that of the comparative example.

Example 2

A preparation method of a Sn-containing super austenitic stainless steel cold-rolled plate, comprising the following steps:

(1) Smelting: According to the composition ratio of super austenitic stainless steel, weigh the raw materials, and weigh 0.25% Sn by mass fraction, heat and dry each raw material at 70°C for 160min, among which, the super austenitic stainless steel The composition mass percentage of stainless steel is: C ≤ 0.03%, N 0.2%, Si 0.5%, Cu 0.4%, Mn 1.0%, Mo 6.5%, Cr 20%, Ni 24%, the balance is Fe and unavoidable impurities, Among them, P ≤ 0.04%, S ≤ 0.03%, O ≤ 0.005%; the raw materials are classified, put into a vacuum induction melting furnace step by step, and smelted in a high vacuum environment with a vacuum degree of 5 Pa to obtain molten steel. Among them, N It is added in the form of ferrochromium nitride, and Sn, Mn and ferrochromium nitride are added in sequence after the rest of the raw materials are completely melted;

(2) Casting: Control the pouring temperature at 1550°C, and under the protection of high-purity nitrogen, pour the smelted molten steel through the tundish into the molten pool of the twin-roll strip casting machine for casting and rolling. Rotate, the casting strip is gradually formed, and the thickness is 3.5mm, the width is 110mm Sn-containing super austenitic stainless steel thin strip, wherein, the casting speed is 35m/min, and the casting force is 55kN;

(3) Temper rolling: The super austenitic stainless steel thin strip prepared above is sent to a two-roll temper rolling mill. At this time, the temperature of the thin strip is 1080°C. At this temperature, the cast strip is subjected to one pass of temper rolling , the rolling deformation is 14.3%, and a thin strip with a thickness of 3 mm, a good plate shape and a certain degree of deformation of the solidified structure is obtained, and then crimped;

(4) Homogenization treatment: The above-mentioned flat-rolled thin strip is subjected to high-temperature homogenization treatment, and then quenched to room temperature. Among them, the temperature of the homogenization treatment is 1200°C, and the time is 120min;

(5) Pickling: Soak the homogenized thin strip in a specific pickling solution for pickling treatment, then wash and dry it with water and alcohol, and use it as the base material of cold-rolled sheet. Wherein, the volume ratio of the pickling solution is HCl:HF:HNO3:H2O=2:3:15:100;

(6) Preparation of cold-rolled sheet: cold-rolled and deformed the strip after pickling, the reduction in a single pass is about 10%, and the total deformation is 66.7%, and finally a super austenite with a thickness of 1.0mm is prepared Cold rolled stainless steel strip;

(7) Anneal the cold-rolled sheet prepared above, and then test its mechanical properties and corrosion resistance. Wherein, the annealing process is 1050° C.×10 min.

After testing, the tensile strength of the stainless steel cold-rolled plate prepared by the present invention is 788MPa, the yield strength is 390MPa, the elongation is 49%, and the pitting point is 1.05V.

In addition, the thin strip cold-rolled sheet of the same thickness prepared in the comparative example was subjected to the same annealing treatment as in Example 2, and the mechanical properties and corrosion resistance were measured. The results showed that the tensile strength of the traditional cold-rolled sheet was 736MPa , the yield strength is 368MPa, the elongation is 43%, the pitting point is 1.00V, the performance of Example 2 is better than that of the comparative example.

Example 3

A preparation method of a Sn-containing super austenitic stainless steel cold-rolled plate, comprising the following steps:

(1) Smelting: According to the composition ratio of super austenitic stainless steel, weigh the raw materials, and weigh 0.05% Sn by mass fraction, heat and dry each raw material at 100°C for 120min, among which, super austenitic stainless steel The composition mass percentage of stainless steel is: C ≤ 0.03%, N 0.2%, Si 0.5%, Cu 0.4%, Mn 1.0%, Mo 6.0%, Cr 20%, Ni 24%, the balance is Fe and unavoidable impurities, Among them, P ≤ 0.04%, S ≤ 0.03%, O ≤ 0.005%; the raw materials are classified, put into a vacuum induction melting furnace step by step, and smelted in a high vacuum environment with a vacuum degree of 4.5 Pa to obtain molten steel. Among them, N It is added in the form of ferrochromium nitride, and Sn, Mn and ferrochromium nitride are added in sequence after the rest of the raw materials are completely melted;

(2) Pouring: Control the pouring temperature at 1570°C, and under the protection of high-purity nitrogen, pour the smelted molten steel through the tundish into the molten pool of the twin-roll strip casting machine for casting and rolling. Rotate, the casting strip is gradually formed, and the thickness is 2.5mm, the width is 254mm Sn-containing super austenitic stainless steel thin strip, wherein, the casting speed is 45m/min, and the casting force is 65kN;

(3) Temper rolling: The super austenitic stainless steel thin strip prepared above is sent to a two-roll temper rolling mill. At this time, the temperature of the thin strip is 1102°C. At this temperature, the cast strip is subjected to one pass of temper rolling , the rolling deformation is 20%, and a thin strip with a thickness of 2.0 mm, a good plate shape and a certain degree of deformation of the solidified structure is obtained, and then crimped;

(4) Homogenization treatment: The above-mentioned flat-rolled thin strip is subjected to high-temperature homogenization treatment, and then quenched to room temperature. Wherein, the temperature of the homogenization treatment is 1250° C., and the time is 30 minutes;

(5) Pickling: Soak the homogenized thin strip in a specific pickling solution for pickling treatment, then wash and dry it with water and alcohol, and use it as the base material of cold-rolled sheet. Wherein, the volume ratio of the pickling solution is HCl:HF:HNO3:H2O=2:3:15:100;

(6) Preparation of cold-rolled sheet: cold-rolled and deformed the strip after pickling, the reduction in a single pass is about 5%, and the total deformation is 40%, and finally a super austenite with a thickness of 1.2mm is prepared Cold rolled stainless steel strip;

(7) Anneal the cold-rolled sheet prepared above, and then test its mechanical properties and corrosion resistance. Wherein, the annealing process is 1050° C.×20 min.

After testing, the tensile strength of the cold-rolled stainless steel plate prepared by the present invention is 771MPa, the yield strength is 375MPa, the elongation is 47%, and the pitting point is 1.02V.

In addition, the thin strip cold-rolled sheet with the same thickness prepared in the comparative example was subjected to the same annealing treatment as in Example 3, and the mechanical properties and corrosion resistance were measured. The results showed that the tensile strength of the traditional cold-rolled sheet was 732MPa , the yield strength is 364MPa, the elongation is 44%, the pitting point is 1.00 V, the performance of Example 3 is better than that of the comparative example.

Example 4

A preparation method of a Sn-containing super austenitic stainless steel cold-rolled plate, comprising the following steps:

(1) Smelting: Weigh the raw materials according to the composition ratio of super austenitic stainless steel, and weigh 0.4% Sn by mass fraction, and heat and dry each raw material at 60°C for 180min. Among them, the super austenitic stainless steel The composition mass percentage of stainless steel is: C ≤ 0.03%, N 0.2%, Si 0.5%, Cu 0.4%, Mn 1.0%, Mo 7.5%, Cr 20%, Ni 24%, the balance is Fe and unavoidable impurities, Among them, P ≤ 0.04%, S ≤ 0.03%, O ≤ 0.005%; classify the raw materials, put them into the vacuum induction melting furnace step by step, and smelt them in a high vacuum environment with a vacuum degree of 4.8Pa to obtain molten steel. Among them, N It is added in the form of ferrochromium nitride, and Sn, Mn and ferrochromium nitride are added in sequence after the rest of the raw materials are completely melted;

(2) Casting: Control the pouring temperature at 1600°C, and under the protection of high-purity nitrogen, pour the smelted molten steel through the tundish into the molten pool of the twin-roll strip casting machine for casting and rolling. Rotate, the casting strip is gradually formed, and the thickness is 3mm, the width is the Sn-containing super austenitic stainless steel thin strip of 254mm, wherein, the casting and rolling speed is 55m/min, and the casting and rolling force is 60kN;

(3) Temper rolling: The super austenitic stainless steel thin strip prepared above is sent to a two-roll temper rolling mill. At this time, the temperature of the cast strip is 1108°C. At this temperature, the cast strip is subjected to one pass of temper rolling , the rolling deformation is 16.7%, and a thin strip with a thickness of 2.5mm, good plate shape and a certain degree of deformation of the solidified structure is obtained, and then crimped;

(4) Homogenization treatment: The above-mentioned flat-rolled thin strip is subjected to high-temperature homogenization treatment, and then quenched to room temperature. Wherein, the temperature of the homogenization treatment is 1250° C., and the time is 30 minutes;

(5) Pickling: Soak the homogenized thin strip in a specific pickling solution for pickling treatment, then wash and dry it with water and alcohol, and use it as the base material of cold-rolled sheet. Wherein, the volume ratio of the pickling solution is HCl:HF:HNO3:H2O=2:3:15:100;

(6) Preparation of cold-rolled sheet: Cold-rolled and deformed the strip after pickling, with a reduction of about 8% in a single pass and a total deformation of 60%, and finally prepared a super austenite with a thickness of 1.0mm Stainless steel cold-rolled plate;

(7) Anneal the cold-rolled sheet prepared above, and then test its mechanical properties and corrosion resistance. Wherein, the annealing process is 1100° C.×15 min.

After testing, the tensile strength of the cold-rolled stainless steel plate prepared by the present invention is 778MPa, the yield strength is 380MPa, the elongation is 48.5%, and the pitting point is 1.02V.

In addition, the thin strip cold-rolled sheet of the same thickness prepared in the comparative example was subjected to the same annealing treatment as in Example 4, and the mechanical properties and corrosion resistance were measured. The results showed that the tensile strength of the traditional cold-rolled sheet was 730MPa , the yield strength is 361MPa, the elongation is 44.7%, the pitting point is 1.0 V, the performance of Example 4 is better than that of the comparative example.

Example 5

A preparation method of a Sn-containing super austenitic stainless steel cold-rolled plate, comprising the following steps:

(1) Smelting: According to the composition ratio of super austenitic stainless steel, weigh the raw materials, and weigh 0.5% Sn by mass fraction, heat and dry each raw material at 50°C for 180min, among which, the super austenitic stainless steel The composition mass percentage of stainless steel is: C ≤ 0.03%, N 0.2%, Si 0.5%, Cu 0.4%, Mn 1.0%, Mo 7%, Cr 20%, Ni 24%, the balance is Fe and unavoidable impurities, Among them, P ≤ 0.04%, S ≤ 0.03%, O ≤ 0.005%; classify the raw materials, put them into the vacuum induction melting furnace step by step, and smelt them in a high vacuum environment with a vacuum degree of 4.8Pa to obtain molten steel. Among them, N It is added in the form of ferrochromium nitride, and Sn, Mn and ferrochromium nitride are added in sequence after the rest of the raw materials are completely melted;

(2) Pouring: The pouring temperature is controlled at 1500°C, and under the protection of high-purity nitrogen, the smelted molten steel is poured into the molten pool of the twin-roll strip casting machine through the tundish for casting and rolling. Rotate, the casting strip is gradually formed, and the thickness is 3mm, the width is the Sn-containing super austenitic stainless steel thin strip of 254mm, wherein, the casting and rolling speed is 35m/min, and the casting and rolling force is 45kN;

(3) Temper rolling: The super austenitic stainless steel thin strip prepared above is sent to a two-roll temper rolling mill. At this time, the temperature of the cast strip is 1050°C. At this temperature, the cast strip is subjected to one pass of temper rolling , the rolling deformation is 16.7%, and a thin strip with a thickness of 2.5mm, good plate shape and a certain degree of deformation of the solidified structure is obtained, and then crimped;

(4) Homogenization treatment: The above-mentioned flat-rolled thin strip is subjected to high-temperature homogenization treatment, and then quenched to room temperature. Among them, the temperature of the homogenization treatment is 1150°C, and the time is 90 minutes;

(5) Pickling: Soak the homogenized thin strip in a specific pickling solution for pickling treatment, then wash and dry it with water and alcohol, and use it as the base material of cold-rolled sheet. Wherein, the volume ratio of the pickling solution is HCl:HF:HNO3:H2O=2:3:15:100;

(6) Preparation of cold-rolled sheet: Cold-rolled and deformed the strip after pickling, with a reduction of about 8% in a single pass and a total deformation of 60%, and finally prepared a super austenite with a thickness of 1.0mm Stainless steel cold-rolled plate;

(7) Anneal the cold-rolled sheet prepared above, and then test its mechanical properties and corrosion resistance. Wherein, the annealing process is 1000° C.×20 min.

After testing, the tensile strength of the stainless steel cold-rolled plate prepared by the present invention is 788MPa, the yield strength is 390MPa, the elongation is 49%, and the pitting point is 1.05V.

In addition, the thin strip cold-rolled sheet with the same thickness prepared in the comparative example was subjected to the same annealing treatment as in Example 5, and the mechanical properties and corrosion resistance were measured. The results showed that the tensile strength of the traditional cold-rolled sheet was 730MPa , the yield strength is 365MPa, the elongation is 44.7%, the pitting point is 1.01 V, the performance of Example 5 is better than that of the comparative example.

Example 6

A preparation method of a Sn-containing super austenitic stainless steel cold-rolled plate, comprising the following steps:

(1) Melting: Weigh the raw materials according to the composition ratio of super austenitic stainless steel, and weigh 0.15% Sn by mass fraction, and heat and dry each raw material at 75°C for 140min. Among them, the super austenitic stainless steel The composition mass percentage of stainless steel is: C ≤ 0.03%, N 0.2%, Si 0.5%, Cu 0.4%, Mn 1.0%, Mo 8%, Cr 20%, Ni 24%, the balance is Fe and unavoidable impurities, Among them, P ≤ 0.04%, S ≤ 0.03%, O ≤ 0.005%; classify the raw materials, put them into the vacuum induction melting furnace step by step, and smelt them in a high vacuum environment with a vacuum degree of 4.6Pa to obtain molten steel. Among them, N It is added in the form of ferrochromium nitride, and Sn, Mn and ferrochromium nitride are added in sequence after the rest of the raw materials are completely melted;

(2) Pouring: Control the pouring temperature at 1520°C, and under the protection of high-purity nitrogen, pour the smelted molten steel through the tundish into the molten pool of the twin-roll strip casting machine for casting and rolling. Rotate, the casting strip is gradually formed, and the thickness is 4mm, the width is 150mm Sn-containing super austenitic stainless steel thin strip, wherein, the casting speed is 40m/min, and the casting and rolling force is 45kN;

(3) Temper rolling: The super austenitic stainless steel thin strip prepared above is sent to a two-roll temper rolling mill. At this time, the temperature of the cast strip is 1120°C. At this temperature, the cast strip is subjected to one pass of temper rolling , with a rolling deformation of 12.5%, to obtain a thin strip with a thickness of 3.5mm, a good plate shape and a certain degree of deformation in the solidified structure, and then crimp;

(4) Homogenization treatment: The above-mentioned flat-rolled thin strip is subjected to high-temperature homogenization treatment, and then quenched to room temperature. Among them, the temperature of the homogenization treatment is 1180°C, and the time is 90 minutes;

(5) Pickling: Soak the homogenized thin strip in a specific pickling solution for pickling treatment, then wash and dry it with water and alcohol, and use it as the base material of cold-rolled sheet. Wherein, the volume ratio of the pickling solution is HCl:HF:HNO3:H2O=2:3:15:100;

(6) Preparation of cold-rolled sheet: cold-rolled and deformed the strip after pickling, the reduction in a single pass is about 8%, and the total deformation is 65.7%, and finally a super austenite with a thickness of 1.2mm is prepared Stainless steel cold-rolled plate;

(7) Anneal the cold-rolled sheet prepared above, and then test its mechanical properties and corrosion resistance. Wherein, the annealing process is 1000° C.×15 min.

After testing, the tensile strength of the cold-rolled stainless steel plate prepared by the present invention is 780MPa, the yield strength is 380MPa, the elongation is 48.5%, and the pitting point is 1.05V.

In addition, the thin strip cold-rolled sheet with the same thickness prepared in the comparative example was subjected to the same annealing treatment as in Example 6, and the mechanical properties and corrosion resistance were measured. The results showed that the tensile strength of the traditional cold-rolled sheet was 735MPa , the yield strength is 361MPa, the elongation is 44%, the pitting point is 1.0 V, the performance of Example 6 is better than that of the comparative example.

Example 7

A preparation method of a Sn-containing super austenitic stainless steel cold-rolled plate, comprising the following steps:

(1) Smelting: According to the composition ratio of super austenitic stainless steel, weigh raw materials, and weigh 0.35% Sn by mass fraction, heat and dry each raw material at 55°C for 160min, among which, super austenitic stainless steel The composition mass percentage of stainless steel is: C ≤ 0.03%, N 0.2%, Si 0.5%, Cu 0.4%, Mn 1.0%, Mo 6.5%, Cr 20%, Ni 24%, the balance is Fe and unavoidable impurities, Among them, P ≤ 0.04%, S ≤ 0.03%, O ≤ 0.005%; the raw materials are classified, put into a vacuum induction melting furnace step by step, and smelted in a high vacuum environment with a vacuum degree of 4Pa to obtain molten steel, where N is Add in the form of ferrochromium nitride, Sn, Mn and ferrochromium nitride are added sequentially after the rest of the raw materials are completely melted;

(2) Pouring: The pouring temperature is controlled at 1500°C, and under the protection of high-purity nitrogen, the smelted molten steel is poured into the molten pool of the twin-roll strip casting machine through the tundish for casting and rolling. Rotate, the casting strip is gradually formed, and the thickness is 3.5mm, the width is 200mm Sn-containing super austenitic stainless steel thin strip, wherein, the casting and rolling speed is 40m/min, and the casting and rolling force is 60kN;

(3) Temper rolling: The super austenitic stainless steel thin strip prepared above is sent to a two-roll temper rolling mill. At this time, the temperature of the cast strip is 1150°C. At this temperature, the cast strip is subjected to one pass of temper rolling , the rolling deformation is 20%, and a thin strip with a thickness of 2.8 mm, a good plate shape and a certain degree of deformation of the solidified structure is obtained, and then crimped;

(4) Homogenization treatment: The above-mentioned flat-rolled thin strip is subjected to high-temperature homogenization treatment, and then quenched to room temperature. Among them, the temperature of the homogenization treatment is 1220°C, and the time is 40 minutes;

(5) Pickling: Soak the homogenized thin strip in a specific pickling solution for pickling treatment, then wash and dry it with water and alcohol, and use it as the base material of cold-rolled sheet. Wherein, the volume ratio of pickling solution is HCl:HF:HNO3:H2O=2:3:15:100;

(6) Preparation of cold-rolled sheet: The strip after pickling is cold-rolled and deformed. The reduction in a single pass is about 8%, and the total deformation is 64.3%. Finally, a super austenitic stainless steel with a thickness of 1mm is prepared. cold rolled plate;

(7) Anneal the cold-rolled sheet prepared above, and then test its mechanical properties and corrosion resistance. Wherein, the annealing process is 1050° C.×15 min.

After testing, the tensile strength of the cold-rolled stainless steel plate prepared by the present invention is 782MPa, the yield strength is 380MPa, the elongation is 48.5%, and the pitting point is 1.04V.

In addition, the thin strip cold-rolled sheet of the same thickness prepared in the comparative example was subjected to the same annealing treatment as in Example 7, and the mechanical properties and corrosion resistance were measured. The results showed that the tensile strength of the traditional cold-rolled sheet was 730MPa , the yield strength is 361MPa, the elongation is 44.7%, the pitting point is 0.99 V, the performance of Example 7 is better than that of the comparative example.

Example 8

A preparation method of a Sn-containing super austenitic stainless steel cold-rolled plate, comprising the following steps:

(1) Smelting: According to the composition ratio of super austenitic stainless steel, weigh the raw materials, and weigh 0.45% Sn by mass fraction, heat and dry each raw material at 70°C for 140min, among which, the super austenitic stainless steel The composition mass percentage of stainless steel is: C ≤ 0.03%, N 0.2%, Si 0.5%, Cu 0.4%, Mn 1.0%, Mo 6%, Cr 20%, Ni 24%, the balance is Fe and unavoidable impurities, Among them, P ≤ 0.04%, S ≤ 0.03%, O ≤ 0.005%; classify the raw materials, put them into the vacuum induction melting furnace step by step, and smelt them in a high vacuum environment with a vacuum degree of 4.6Pa to obtain molten steel. Among them, N It is added in the form of ferrochromium nitride, and Sn, Mn and ferrochromium nitride are added in sequence after the rest of the raw materials are completely melted;

(2) Pouring: Control the pouring temperature at 1520°C, and under the protection of high-purity nitrogen, pour the smelted molten steel through the tundish into the molten pool of the twin-roll strip casting machine for casting and rolling. Rotate, the casting strip is gradually formed, and the thickness is 4mm, the width is 150mm Sn-containing super austenitic stainless steel thin strip, wherein, the casting speed is 40m/min, and the casting and rolling force is 45kN;

(3) Temper rolling: The super austenitic stainless steel thin strip prepared above is sent to a two-roll temper rolling mill. At this time, the temperature of the cast strip is 1120°C. At this temperature, the cast strip is subjected to one pass of temper rolling , with a rolling deformation of 12.5%, to obtain a thin strip with a thickness of 3.5mm, a good plate shape and a certain degree of deformation in the solidified structure, and then crimp;

(4) Homogenization treatment: The above-mentioned flat-rolled thin strip is subjected to high-temperature homogenization treatment, and then quenched to room temperature. Among them, the temperature of the homogenization treatment is 1220°C, and the time is 30 minutes;

(5) Pickling: Soak the homogenized thin strip in a specific pickling solution for pickling treatment, then wash and dry it with water and alcohol, and use it as the base material of cold-rolled sheet. Wherein, the volume ratio of pickling solution is HCl:HF:HNO3:H2O=2:3:15:100;

(6) Preparation of cold-rolled sheet: cold-rolled and deformed the strip after pickling, with a reduction of about 10% in a single pass and a total deformation of 85.7%, and finally prepared a super austenite with a thickness of 0.5mm Stainless steel cold-rolled plate;

(7) Anneal the cold-rolled sheet prepared above, and then test its mechanical properties and corrosion resistance. Wherein, the annealing process is 1000° C.×20 min.

After testing, the tensile strength of the cold-rolled stainless steel plate prepared by the present invention is 788MPa, the yield strength is 385MPa, the elongation is 48.5%, and the pitting point is 1.05V.

In addition, the thin strip cold-rolled sheet of the same thickness prepared in the comparative example was subjected to the same annealing treatment as in Example 8, and the mechanical properties and corrosion resistance were measured. The results showed that the tensile strength of the traditional cold-rolled sheet was 728MPa , the yield strength is 360MPa, the elongation is 45%, the pitting point is 1.0 V, the performance of Example 8 is better than that of the comparative example.

Claims (9)

1. a preparation method containing Sn super austenitic stainless steel cold-rolled sheet, is characterized in that, comprises the following processing steps: (1) Smelting: Weigh the super austenitic stainless steel with a Sn mass content of 0.05~0.5% according to the composition ratio, heat and dry the weighed raw materials at 50~100°C for 120~180min, and classify the raw materials. Put it into a vacuum induction melting furnace step by step, and smelt it in a high vacuum environment with a vacuum degree of 4~5 Pa to obtain molten steel; (2) Casting: Control the pouring temperature between 1500~1600°C, and under the protection of high-purity nitrogen, pour the smelted molten steel into the molten pool of the twin-roll strip casting machine through the tundish for casting and rolling; With the rotation of the casting roll, the casting strip is gradually formed, and a near-net super austenitic stainless steel thin strip with a thickness of 2.5-4 mm and a width of 110-254 mm is prepared. Rolling force 45~65kN; (3) Temper rolling: The near-network super austenitic stainless steel strip prepared above is sent to a two-roll temper rolling mill. At this time, the temperature of the strip is between 1050 and 1150°C. The thin strip is tempered one time, and the rolling deformation is 12.5%~20%; a thin strip with a thickness of 2-3.5mm is obtained, and then crimped; (4) Homogenization treatment: Under the protection of high-purity Ar or in a vacuum environment, perform high-temperature homogenization treatment on the above-mentioned thin strip that has been tempered and rolled. room temperature; (5) Pickling: Soak and pickle the homogenized ribbon in the pickling solution, the volume ratio of the pickling solution is HCl:HF:HNO ₃ :H ₂ O =2:3:15 : 100; Then clean and dry with clear water and alcohol, as the base material of cold-rolled sheet; (6) Preparation of cold-rolled sheet: cold-rolled and deformed the strip after pickling, and obtained a cold-rolled sheet product of super austenitic stainless steel strip through a total deformation of 40-85.7%; (7) Annealing the prepared cold-rolled sheet product and then quenching to room temperature. 2. A method for preparing a Sn-containing super austenitic stainless steel cold-rolled sheet according to claim 1, wherein the composition mass percentage of the super austenitic stainless steel described in step (1) is: C ≤ 0.03%, N 0.18 ~ 0.25%, Si ≤ 1.0%, Cu ≤ 1.0%, Mn ≤ 2.0%, Mo 5 ~ 7%, Cr 20 ~ 22%, Ni 23.5 ~ 25.5%, the balance is Fe and unavoidable Impurities, among them, P ≤ 0.04%, S ≤ 0.03%, O ≤ 0.005%. 3. A method for preparing a Sn-containing super austenitic stainless steel cold-rolled sheet according to claim 2, wherein N is added in the form of ferrochromium nitride in step (1), and Sn, Mn and nitrogen Ferrochrome is added sequentially after other raw materials are completely melted. 4. A method for preparing a Sn-containing super austenitic stainless steel cold-rolled sheet according to claim 1, 2 or 3, characterized in that the single-pass deformation of the cold-rolled deformation in step (6) is 5.7 %~20%. 5. A method for preparing a Sn-containing super austenitic stainless steel cold-rolled sheet according to claim 1, 2 or 3, characterized in that the thickness of the cold-rolled sheet product described in step (6) is 0.5-1.2mm . 6. The method for preparing a Sn-containing super austenitic stainless steel cold-rolled sheet according to claim 4, characterized in that the thickness of the cold-rolled sheet product in step (6) is 0.5-1.2mm. 7. A method for preparing a Sn-containing super austenitic stainless steel cold-rolled sheet according to claim 1 or 2 or 3 or 6, characterized in that the annealing temperature of the cold-rolled sheet in step (7) is 1000~ 1100℃, the treatment time is 5~20min. 8. A method for preparing a Sn-containing super austenitic stainless steel cold-rolled sheet according to claim 4, characterized in that the annealing temperature of the cold-rolled sheet in step (7) is 1000-1100°C, and the processing time is 5~20min. 9. A method for preparing a Sn-containing super austenitic stainless steel cold-rolled sheet according to claim 5, characterized in that the annealing temperature of the cold-rolled sheet in step (7) is 1000-1100°C, and the processing time is 5~20min.