CN105441802B - Titanium-containing acid pickling plate and preparation method thereof - Google Patents

Abstract

The invention belongs to the field of steel and iron smelting and particularly relates to a titanium-containing acid pickling plate and a preparation method thereof. The titanium-containing acid pickling plate is prepared from, by weight, not larger than 0.05% of C, not larger than 0.05% of Si, not larger than 0.40% of Mn, not larger than 0.025% of P, not larger than 0.025% of S, not larger than 0.03% of Ti and the balance Fe and inevitable impurities. The invention provides the titanium-containing acid pickling plate excellent in performance and the preparation method of the titanium-containing acid pickling plate. Mainly, by controlling the rolling, cooling and acid pickling tension leveling technology of the titanium-containing acid pickling plate, on one hand, an acid pickling plate yield platform is effectively eliminated, on the other hand, original mobile dislocation density is increased, and therefore the cross break defect of the acid pickling plate lower in yield strength is inhibited. The beneficial effects of being simple in method, low in production cost and excellent in product performance and welding performance are achieved.

Description

A kind of titanium-containing acid washing plate and its preparation method

technical field

The invention belongs to the field of iron and steel smelting, and in particular relates to a titanium-containing pickled plate and a preparation method thereof.

Background technique

The pickling plate is made of high-quality hot-rolled sheet as raw material. The pickling unit removes the oxide layer, trims the edge, and finishes. The main processes include hot-rolled raw material decoiling→laser welding→phosphorus breaking by the tension-leveling unit→turbulent pickling→rinsing→ On-line leveling→edge trimming→on-line oiling→baling→packing and storage, its surface quality and use requirements are between hot-rolled and cold-rolled sheets, and it is an ideal substitute for some hot-rolled and cold-rolled sheets.

The titanium-containing pickling plate is to add a certain amount of titanium alloy to the ordinary pickling plate. The main function is to fix the C and N interstitial atoms in the low carbon steel, and the other function is to improve the welding performance of the finished product.

Pickling board is a developing steel product. At present, the market demand is mainly concentrated in the automobile industry, compressor industry, machinery manufacturing industry, spare parts processing industry, fan industry, motorcycle industry, steel furniture, hardware accessories, electric cabinet shelves and Stamping parts of various shapes, etc. With the advancement of technology, hot-rolled pickled plates have been involved in household appliances, containers, electrical control cabinets and other industries, and the use of hot-rolled pickled plates instead of cold plates has developed rapidly in some industries.

The application number is "201210175585.1", and the title of the invention is "A hot-rolled pickling plate for automobile structure containing Cr and its production method", which discloses a steel sheet containing C: 0.11-0.15%, Si≤0.05%, Mn0.60 ～1.20%, Cr 0.20～0.40%, Ti 0.01～0.02%, P≤0.02%, S≤0.010%, Als 0.02～0.07%, and the balance of Fe and unavoidable impurities, the above are all acid by weight percentage wash board. Among them, the content of C, Mn, and Cr in this patent is high, and the strength of the steel is high. The strength of the prepared pickling plate reaches 440MPa, which is suitable for high-strength structural steel such as automobiles. This type of steel itself is not easy to produce transverse bending defects.

The application number is "201410681628.2", and the title of the invention is "a hot-rolled pickling plate and its production method", which discloses a method based on the composition system of ordinary low-carbon steel, by rationally adding microalloying elements B and Ti, and combining The heat preservation of the hot coil box before finishing rolling and the cooling after finishing rolling can finally control the structure and precipitated phase, reduce the effect of Coriolis air mass in the low carbon steel, and reduce the stress difference between the upper and lower yield points of the hot-rolled strip to below 5MPa, eliminating thermal stress. Surface fold defects in the pickling uncoiling and straightening process of the rolled plate; the chemical composition of the pickled plate is as follows: C0.02-0.06%, Si 0.005-0.02%, Mn0.05-0.3%, Ti 0.01- 0.1%, B 0.001-0.005%, Al 0.01-0.1%, P≤0.03%, S≤0.01%, and the rest are Fe and unavoidable impurities. Boron is added in this patent. It is difficult to control the accuracy of the composition of boron, and when the boron content is high, the steel plate will be brittle and deteriorate the performance of the steel plate.

Contents of the invention

In order to overcome the deficiencies of the prior art, the first technical problem to be solved by the present invention is to provide a method that can effectively eliminate the yield platform of the pickled plate and increase the original movable dislocation density, thereby suppressing the lower yield strength of the pickled plate. The acid-washed plate containing titanium with cross-folding defects is simple and feasible for industrial production.

A titanium-containing pickling plate of the present invention is composed of the following chemical components in weight percentage: C≤0.05%, Si≤0.05%, Mn≤0.40%, P≤0.025%, S≤0.025%, Ti≤0.03%, and the rest is Fe and unavoidable impurities.

Further, as a more preferred technical solution, the above-mentioned titanium-containing pickling plate is composed of the following chemical components in weight percent: C 0.01-0.05%, Si 0.01-0.05%, Mn 0.15-0.40%, P≤0.015 %, S≤0.010%, Ti 0.012～0.03%, and the rest are Fe and unavoidable impurities.

Further, as a more preferred technical solution, the above-mentioned titanium-containing pickling plate is composed of the following chemical components in weight percent: C 0.01-0.05%, Si 0.01-0.03%, Mn 0.15-0.39%, P 0.012- 0.015%, S 0.008-0.010%, Ti 0.012-0.025%, and the rest are Fe and unavoidable impurities.

Further, as a more preferred technical solution, the aforementioned titanium-containing pickling plate is composed of the following chemical components in weight percent: C 0.05%, Si 0.02%, Mn 0.15%, P 0.012%, S 0.010%, Ti 0.019%, the rest is Fe and unavoidable impurities.

The titanium-containing acid-washed plate mentioned above has a yield strength of 190-250 MPa, a tensile strength of 300-350 MPa, and an elongation of ≥45%.

The second technical problem to be solved by the present invention is to provide a method for preparing a titanium-containing pickled plate with simple method, low production cost, excellent product formability and welding performance.

The above-mentioned method for preparing a titanium-containing pickled plate mainly includes the following steps: steel billet → hot rolling → laminar cooling → coiling → pickling;

Among them, the start rolling temperature of the finish rolling in the hot rolling step is 950-1050°C, the finishing rolling temperature in the hot rolling step is 830-900°C; the coiling temperature is 540-598°C; the tensile elongation in the pickling step is 0.8-3.0%.

Further, as a more preferred technical solution, in the above-mentioned method for preparing a titanium-containing pickled plate, the starting temperature of the finish rolling in the hot rolling step is 952-1048° C., and the finishing rolling temperature in the hot rolling step is 834-1048° C. 897°C; the coiling temperature is 545-598°C; the tensile elongation in the pickling step is 0.8-2.5%.

Further, as a more preferred technical solution, in the above-mentioned method for preparing a titanium-containing pickled plate, the starting temperature of the finish rolling in the hot rolling step is 1048°C, and the finishing rolling temperature in the hot rolling step is 897°C; The temperature is taken as 598° C.; the tensile elongation in the pickling step is 2.5%.

The invention provides a titanium-containing pickling plate with excellent performance and a production method thereof, mainly through controlling the rolling, cooling process and pickling tension leveling process of the titanium-containing pickling plate, on the one hand, effectively eliminating the yield platform of the pickling plate, On the other hand, the original movable dislocation density is increased, thereby suppressing the cross-folding defect of the pickling plate with lower yield strength, and has the advantages of simple method, low production cost, excellent product formability and welding performance.

detailed description

A titanium-containing pickling plate of the present invention is composed of the following chemical components in weight percentage: C≤0.05%, Si≤0.05%, Mn≤0.40%, P≤0.025%, S≤0.025%, Ti≤0.03%, and the rest is Fe and unavoidable impurities.

Further, as a more preferred technical solution, the above-mentioned titanium-containing pickling plate is composed of the following chemical components in weight percent: C 0.01-0.05%, Si 0.01-0.05%, Mn 0.15-0.40%, P≤0.015 %, S≤0.010%, Ti 0.012～0.03%, and the rest are Fe and unavoidable impurities.

Further, as a more preferred technical solution, the above-mentioned titanium-containing pickling plate is composed of the following chemical components in weight percent: C 0.01-0.05%, Si 0.01-0.03%, Mn 0.15-0.39%, P 0.012- 0.015%, S 0.008-0.010%, Ti 0.012-0.025%, and the rest are Fe and unavoidable impurities.

Further, as a more preferred technical solution, the aforementioned titanium-containing pickling plate is composed of the following chemical components in weight percent: C 0.05%, Si 0.02%, Mn 0.15%, P 0.012%, S 0.010%, Ti 0.019%, the rest is Fe and unavoidable impurities.

The titanium-containing acid-washed plate mentioned above has a yield strength of 190-250 MPa, a tensile strength of 300-350 MPa, and an elongation of ≥45%.

The above-mentioned method for preparing a titanium-containing pickled plate mainly includes the following steps: steel billet → hot rolling → laminar cooling → coiling → pickling;

Among them, the start rolling temperature of the finish rolling in the hot rolling step is 950-1050°C, the finishing rolling temperature in the hot rolling step is 830-900°C; the coiling temperature is 540-598°C; the tensile elongation in the pickling step is 0.8-3.0%.

Further, as a more preferred technical solution, in the above-mentioned method for preparing a titanium-containing pickled plate, the starting temperature of the finish rolling in the hot rolling step is 952-1048° C., and the finishing rolling temperature in the hot rolling step is 834-1048° C. 897°C; the coiling temperature is 545-598°C; the tensile elongation in the pickling step is 0.8-2.5%.

Further, as a more preferred technical solution, in the above-mentioned method for preparing a titanium-containing pickled plate, the starting temperature of the finish rolling in the hot rolling step is 1048°C, and the finishing rolling temperature in the hot rolling step is 897°C; The temperature is taken as 598° C.; the tensile elongation in the pickling step is 2.5%.

Wherein, in the hot rolling step, the finish rolling start temperature is 950-1050°C, if the temperature is too low, the rolling rhythm is too slow, and the production efficiency is low; if the temperature is too high, the cooling speed of the rolling process is too fast, and the structure is uneven, resulting in The overall performance of the finished product is poor.

In the hot rolling step, the final rolling temperature is 830-900°C. If the temperature is too low, the stability of thin-gauge rolling is poor, and broken strips or surface defects are likely to occur; if the temperature is too high, the cooling rate is too fast, the structure is uneven, and easy to produce Three oxide scales.

The temperature in the coiling step is 540-598° C. If the temperature is too low, bainite structure is easily formed and the elongation rate is low; if the temperature is too high, the finished product has coarse grains and low dislocation density.

The tensile elongation in the pickling step is 0.5-3.0%. If the elongation is too low, the scale-breaking effect of tensile straightening will not be achieved; if the elongation is too high, work hardening will easily occur and product performance will deteriorate.

Compared with the prior art, the titanium-containing pickling plate produced by the invention has low strength, high elongation, excellent stamping performance, and also solves the problem that soft steel is prone to transverse bending defects.

The specific implementation of the present invention will be further described below in conjunction with the examples, and the present invention is not limited to the scope of the examples.

Example 1

The weight percent of the chemical composition of the billet is: C: 0.01%, Si: 0.01%, Mn: 0.39%, P: 0.015%, S: 0.009%, Ti: 0.025%, and the rest is Fe and unavoidable impurities.

The preparation method of titanium-containing pickled plate mainly includes the following steps: billet → hot rolling → laminar cooling → coiling → pickling:

Among them, the finish rolling start temperature in the hot rolling step is 952°C, the finish rolling temperature in the hot rolling step is 834°C; the temperature in the coiling step is 545°C; the tensile elongation in the pickling step is 0.8%.

The mechanical properties of the titanium-containing acid-washed plate produced by the method Rel: 192MPa, Rm: 300MPa, A%: 50%; the surface quality is good.

Example 2

The weight percent of the chemical composition of the billet is: C: 0.03%, Si: 0.03%, Mn: 0.20%, P: 0.013%, S: 0.008%, Ti: 0.012%, and the rest is Fe and unavoidable impurities.

The preparation method of titanium-containing pickled plate mainly includes the following steps: billet → hot rolling → laminar cooling → coiling → pickling:

Among them, the finish rolling start temperature in the hot rolling step is 1005°C, the finish rolling temperature in the hot rolling step is 872°C; the temperature in the coiling step is 575°C; the tensile elongation in the pickling step is 1.9%.

The mechanical properties of the titanium-containing acid-washed plate produced by the method Rel: 214MPa, Rm: 319MPa, A%: 49%; the surface quality is good.

Example 3

The weight percent of the chemical composition of the billet is: C: 0.05%, Si: 0.02%, Mn: 0.15%, P: 0.012%, S: 0.010%, Ti: 0.019%, and the rest is Fe and unavoidable impurities.

The preparation method of titanium-containing pickled plate mainly includes the following steps: billet → hot rolling → laminar cooling → coiling → pickling:

Among them, the finish rolling start temperature in the hot rolling step is 1048°C, the finish rolling temperature in the hot rolling step is 897°C; the temperature in the coiling step is 598°C; the tensile elongation in the pickling step is 2.5%.

The mechanical properties of the titanium-containing acid-washed plate produced by the method Rel: 227MPa, Rm: 334MPa, A%: 48%; the surface quality is good.

Claims (4)

1. A titanium-containing pickling board, composed of the following chemical components in weight percentage: C 0.05%, Si 0.02%, Mn 0.15%, P 0.012%, S 0.010%, Ti 0.019%, the rest is Fe and unavoidable impurities; The preparation method mainly includes the following steps: steel billet → hot rolling → laminar cooling → coiling → pickling, wherein the starting temperature of finish rolling in the hot rolling step is 950-1050°C, and the finishing rolling temperature in the hot rolling step is 830-830°C. 900°C; the coiling temperature is 540-598°C; the tensile elongation in the pickling step is 0.8-3.0%; The yield strength of the titanium-containing acid-washed plate is 190-250MPa, the tensile strength is 300-350MPa, and the elongation is ≥45%. 2. The preparation method of a titanium-containing pickling plate according to claim 1, the method mainly comprises the following steps: steel billet → hot rolling → laminar cooling → coiling → pickling, it is characterized in that: in the hot rolling step, finish rolling The starting rolling temperature is 950-1050°C, the final rolling temperature in the hot rolling step is 830-900°C; the coiling temperature is 540-598°C; the tensile elongation in the pickling step is 0.8-3.0%. 3. A method for preparing a titanium-containing pickled plate according to claim 2, characterized in that: the starting temperature of finish rolling in the hot rolling step is 952-1048° C., and the finishing rolling temperature in the hot rolling step is 834-897° C. °C; the coiling temperature is 545-598 °C; the tensile elongation in the pickling step is 0.8-2.5%. 4. A method for preparing a titanium-containing pickled plate according to claim 2, characterized in that: the start rolling temperature of the finish rolling in the hot rolling step is 1048°C, and the finishing rolling temperature in the hot rolling step is 897°C; The temperature was 598°C; the tensile elongation in the pickling step was 2.5%.