CN116083815A - Wear-resistant stainless steel and preparation process thereof - Google Patents

Abstract

The application relates to the field of stainless steel, in particular to wear-resistant stainless steel and a preparation process thereof. The wear-resistant stainless steel comprises the following substances in percentage by mass: c is less than 0.08%; si is 1% or less; mn is 1-3%; p is less than 0.035%; s is less than 0.03%; cu is 1.5-2.8%; cr is 23-27%; mo is 2-4.0%; ni is 4-9%; the balance of Fe and unavoidable impurities; the microstructure is ferrite and austenite as a matrix; the preparation method comprises the following steps: melting Fe into molten iron at high temperature, adding each element into the molten iron, casting, cooling and forming to obtain a workpiece; and heating the workpiece, placing the workpiece into a box-type electric furnace, heating and preserving heat, discharging the workpiece, cooling the workpiece by water, charging the workpiece into the furnace again within 30 seconds, heating and preserving heat, discharging the workpiece from the furnace, and cooling the workpiece in air to obtain the wear-resistant stainless steel. The stainless steel has the advantage of improving the wear resistance of the stainless steel.

Description

A kind of wear-resistant stainless steel and its preparation process

technical field

The present application relates to the field of stainless steel, in particular to a wear-resistant stainless steel and a preparation process thereof.

Background technique

Duplex stainless steel refers to stainless steel with ferrite and austenite matrix, and the content of less phase generally needs to reach at least 30%. In the case of low C content, the Cr content is 18%-28%, and the Ni content is 3%-10%. Some steels also contain alloying elements such as Mo, Cu, Nb, Ti, and N. This type of steel has the characteristics of both austenitic and ferritic stainless steels. Compared with ferrite, it has higher plasticity and toughness, no room temperature brittleness, significantly improved intergranular corrosion resistance and welding performance, while maintaining iron The body stainless steel is brittle at 475°C, has high thermal conductivity, and has the characteristics of superplasticity. Compared with austenitic stainless steel, it has high strength and significantly improved resistance to intergranular corrosion and chloride stress corrosion. Duplex stainless steel has excellent pitting corrosion resistance and is also a nickel-saving stainless steel.

Due to the characteristics of the two-phase structure, through the correct control of the chemical composition and heat treatment process, the duplex stainless steel has the advantages of both ferritic stainless steel and austenitic stainless steel. It combines the excellent toughness and weldability of austenitic stainless steel with iron The higher strength and chloride stress corrosion resistance of ferritic stainless steels are combined.

However, the existing stainless steel usually pays more attention to corrosion resistance. In order to maintain its corrosion resistance at a high value, corrosion-resistant elements are usually added, resulting in a decrease in the wear resistance of stainless steel. When stainless steel is used in harsh working conditions When used in the environment, stainless steel can only withstand the corrosion caused by harsh working conditions, but cannot withstand the wear and tear on stainless steel caused by harsh working conditions, resulting in damage to stainless steel.

Contents of the invention

In order to improve the wear-resistant strength of stainless steel, the application provides a wear-resistant stainless steel and a preparation process thereof.

In the first aspect, the present application provides a kind of wear-resistant stainless steel, adopting the following technical scheme:

A wear-resistant stainless steel, the wear-resistant stainless steel includes the following substances by mass percentage:

C content is less than 0.08%;

Si content is less than 1.0%;

Mn content is 1.0%-3.0%;

P content is below 0.035%;

The S content is below 0.030%;

Cu content is 1.5%-2.8%;

The Cr content is 23.0%-27.0%;

Mo content is 2.0%-4.0%;

Ni content is 4.0%-9.0%;

The balance is Fe and unavoidable impurities;

The microstructure is ferrite and austenite as the matrix, and it also contains precipitation hardening phase after heat treatment.

By adopting the above technical scheme, Cr, Mo, and Ni are the key elements affecting the corrosion resistance of stainless steel. When the contents of the three elements are different, they have different effects on the corrosion resistance and wear resistance of duplex stainless steel. When Cr When the content of Ni and Mo elements increases, the corrosion resistance of ferrite and austenite will gradually increase, and when the content of Ni element increases, the corrosion resistance of ferrite will gradually increase, and the corrosion resistance of austenite will gradually increase. Therefore, the Ni content needs to find an optimal point, so that the corrosion resistance of ferrite and austenite is relatively balanced; the corrosion resistance is greatly enhanced without reducing the corrosion performance, and it solves the problem of both corrosion resistance and corrosion resistance. The use of materials in harsh working conditions with high wear resistance; C is also the main factor determining the corrosion resistance of materials. The higher the C content, the worse the corrosion resistance of the material, and the lower the C content, the higher the cost of the material. The cost-effective content is not more than 0.08%. The addition of Si can improve the deoxidation performance of molten steel casting, but too high Si content will affect the plasticity and corrosion resistance of the material; P and S are harmful elements in stainless steel. It has a significant impact on the plasticity and corrosion resistance of the material, and they are required to be no more than 0.035% and 0.030% respectively for cost considerations.

Preferably, the wear-resistant stainless steel also includes RE, and the RE content is less than 0.10%.

By adopting the above technical scheme, the main function of RE is to increase the amount of austenite, refine the grains, and improve the comprehensive mechanical properties of stainless steel, especially the hardness of stainless steel after heat treatment, and the plasticity of the material after the hardness of stainless steel is increased.

Preferably, the content of the ferrite is 50%-70%, the content of the austenite is 30%-50%, and the content of the precipitation hardened phase after heat treatment is 5%-10%.

By adopting the above technical scheme, ferrite can dissolve S, P, and Si elements, prevent element segregation and form low-melting eutectics, thereby preventing solidification cracks, and the existence of ferrite can also disrupt single austenite The directionality of the structure, so as to avoid the concentrated channel of the corrosive medium formed by the poor Cr layer running through the grains; the δ phase ferrite is rich in Cr, and chromium carbide can preferentially precipitate at the edge of the δ phase, and will not be on the surface of the austenite grains The formation of a chromium-poor layer is also beneficial to improve the intergranular corrosion resistance of the weld; but when the ferrite content is too much, the mechanical properties such as strength and ductility of the material will be reduced, making the material more brittle and less tough. Cracks are easy to occur, and too much ferrite will affect the corrosion resistance of austenite, which will reduce the corrosion resistance of the material. This application controls the content of ferrite and austenite by controlling the content of each element. The phase ratio between ferrite and austenite is better balanced, so that stainless steel has better corrosion resistance and higher strength.

Preferably, the Cr content is 24.0%-26.0%.

By adopting the above technical scheme, Cr is the main ferrite matrix element, in order to ensure that the ferrite matrix of the material is not less than 50% and the requirements of corrosion resistance, the content of Cr is further limited, and the content of Cr is set at no It is less than 24%, and because if the content of Cr exceeds 27%, the ferrite matrix will be greater than 70%, so in order to ensure that the ferrite matrix is less than 70%, the content of Cr is further limited to not more than 26%.

Preferably, the Mo content is 2.5%-3.5%.

By adopting the above technical scheme, Mo is a secondary element to form the ferrite matrix, and the addition of Mo can significantly improve the corrosion resistance of the material, especially in the acidic medium containing chloride ions. In order to consider the cost performance of the material, therefore Control the Mo content at 2.5%-3.5%.

Preferably, the Ni content is 5.0%-8.0%.

By adopting the above technical scheme, Ni is the main element for forming the austenitic matrix, improving the corrosion resistance of acid, and improving the plasticity of the material, thereby improving the hardness of the material, and in order to ensure that the australoid matrix is between 30% and 50% , the Ni content is controlled at 5.0%-8.0%.

Preferably, the Mn content is 1.5%-2.5%.

By adopting the above-mentioned technical scheme, Mn is a secondary element for forming the matrix element of the australite, and adding 1.5%-2.5% of Mn cooperates with Ni to form the matrix of the australite, thereby improving the cost performance of the material.

Preferably, the Cu content is 1.8%-2.5%.

By adopting the above technical scheme, Cu improves the corrosion resistance of stainless steel to acid, especially the corrosion resistance to sulfuric acid. When the Cu content is less than 1.5%, the acid corrosion performance is significantly reduced, and when it is greater than 2.8%, the material after heat treatment The plasticity of copper will be significantly worse, resulting in a decrease in the hardness of stainless steel, and complex parts are easy to crack. Therefore, considering the range of Cu at 1.8%-2.5%, the corrosion resistance and hardness of stainless steel are both better.

In the second aspect, the present application provides a preparation process of wear-resistant stainless steel, which adopts the following technical scheme:

A preparation process of wear-resistant stainless steel, comprising the following steps:

Step 1: The workpiece is cast and molded, and Fe is melted into molten iron at high temperature, and then accurately measured elements such as C, Si, Mn, P, S, Cu, Cr, Mo, Ni and RE are added to the molten iron, and mixed evenly Casting into the mould, cooling and molding to obtain the workpiece;

Step 2: heat treatment of the workpiece, preheat the box-type electric furnace, the temperature is not higher than 200°C, then put the workpiece into the box-type electric furnace, raise the temperature of the box-type electric furnace to 1000-1200°C, keep it warm for 2-3 hours, and then Take the workpiece directly out of the furnace and cool it in water, and the time is controlled within 30 seconds. The cooled workpiece is put into the furnace again, and the temperature is directly raised to 790-830°C, and it is kept for 1-2 hours. Finally, the workpiece is cooled to room temperature in the air, and the resistant Grind stainless steel.

By adopting the above-mentioned technical scheme, this application formulates the heat treatment steps most suitable for this application according to the content of each element, and by controlling the first heating control temperature, tempering temperature, holding time and cooling rate, thereby improving the hardness of the formed stainless steel, Improve the plasticity of the product.

In summary, the application has the following beneficial effects:

1. Because this application controls the content of elements C, Cr, Ni, Mo, Mn, and Cu, the ferrite and austenite are in a relatively balanced ratio, so that stainless steel has both good corrosion resistance and good corrosion resistance. The hardness of stainless steel is improved, the corrosion resistance of stainless steel is greatly enhanced, and the problem of using materials in harsh working conditions that require both corrosion resistance and high wear resistance is solved.

2. In this application, element RE is also added to increase the amount of austenite, refine grains, and improve the comprehensive mechanical properties of stainless steel, especially the hardness of stainless steel after heat treatment, and the plasticity of the material after the hardness of stainless steel is improved.

3. The method of this application controls the first heating control temperature, tempering temperature, holding time and cooling rate, thereby increasing the hardness of the stainless steel after forming and improving the plasticity of the product.

Detailed ways

Example

Example 1

A wear-resistant stainless steel, which comprises the following substances in terms of mass percentage: C content is 0.06%; Si content is 0.8%; Mn content is 1.65%; P content is 0.030%; S content is 0.020%; Cu content is 2.0%; Cr content is 24.2%; Mo content is 2.6%; Ni content is 5.5%; RE content is 0.1%; the balance is Fe and unavoidable impurities;

A preparation process of wear-resistant stainless steel, comprising the following steps:

Step 1: The workpiece is cast and molded, and Fe is melted into molten iron at high temperature, and then accurately measured elements such as C, Si, Mn, P, S, Cu, Cr, Mo, Ni and RE are added to the molten iron, and mixed evenly Casting into the mould, cooling and molding to obtain the workpiece;

Step 2: heat treatment of the workpiece, preheat the box-type electric furnace, the temperature is not higher than 200°C, then put the workpiece into the box-type electric furnace, raise the temperature of the box-type electric furnace to 1000-1200°C, keep it warm for 2-3 hours, and then Take the workpiece directly out of the furnace and cool it in water, and the time is controlled within 30 seconds. The cooled workpiece is put into the furnace again, and the temperature is directly raised to 790-830°C, and it is kept for 1-2 hours. Finally, the workpiece is cooled to room temperature in the air, and the resistant Grinding stainless steel

Step 2: Heat treatment of the workpiece, preheat the box-type electric furnace at a temperature of 150°C, then put the workpiece into the box-type electric furnace, raise the temperature to 1080°C, keep it warm for 2.5 hours, and then directly take the workpiece out of the furnace and put it in water to cool, the time is controlled at Within 30 seconds, the cooled workpiece is put into the furnace again, directly heated to 810°C, and kept for 1.5 hours, and finally the workpiece is released from the furnace and cooled to room temperature in the air to produce wear-resistant stainless steel;

The prepared wear-resistant stainless steel has a ferrite content of 54%, an austenite content of 46%, and a precipitation hardening phase content of 7.9% after heat treatment.

Example 2

The difference between embodiment 2 and embodiment 1 is: a kind of wear-resistant stainless steel, which comprises the following substances by mass percentage: C content is 0.06%; Si content is 0.8%; Mn content is 1.65%; P content is 0.030%; The content of Cu is 0.020%; the content of Cu is 2.0%; the content of Cr is 25.8%; the content of Mo is 2.6%; the content of Ni is 5.5%; the content of RE is 0.1%; The ferrite content of ground stainless steel is 67%, the austenite content is 33%, and the precipitation hardening phase content after heat treatment is 8.2%.

Example 3

The difference between embodiment 3 and embodiment 1 is: a kind of wear-resistant stainless steel, which comprises the following substances by mass percentage: C content is 0.06%; Si content is 0.8%; Mn content is 1.65%; P content is 0.030%; The content of Cu is 0.020%; the content of Cu is 2.0%; the content of Cr is 25.0%; the content of Mo is 2.6%; the content of Ni is 5.5%; the content of RE is 0.1%; The ferrite content of ground stainless steel is 62%, the austenite content is 38%, and the precipitation hardening phase content after heat treatment is 7.9%.

Example 4

The difference between embodiment 4 and embodiment 1 is: a kind of wear-resistant stainless steel, which comprises the following substances by mass percentage: C content is 0.06%; Si content is 0.8%; Mn content is 1.65%; P content is 0.030%; The content of Cu is 0.020%; the content of Cu is 2.0%; the content of Cr is 25.0%; the content of Mo is 3.5%; the content of Ni is 5.5%; the content of RE is 0.1%; The ferrite content of ground stainless steel is 64%, the austenite content is 36%, and the precipitation hardening phase content after heat treatment is 8.0%.

Example 5

The difference between embodiment 5 and embodiment 1 is: a kind of wear-resistant stainless steel, which comprises the following substances by mass percentage: C content is 0.06%; Si content is 0.8%; Mn content is 1.65%; P content is 0.030%; The content of Cu is 0.020%; the content of Cu is 2.0%; the content of Cr is 25.0%; the content of Mo is 3.1%; the content of Ni is 5.5%; the content of RE is 0.1%; The ferrite content of ground stainless steel is 63.4%, the austenite content is 36.6%, and the precipitation hardening phase content after heat treatment is 7.9%.

Example 6

The difference between embodiment 6 and embodiment 1 is: a kind of wear-resistant stainless steel, which includes the following substances by mass percentage: C content is 0.06%; Si content is 0.8%; Mn content is 1.65%; P content is 0.030%; S The content of Cu is 0.020%; the content of Cu is 2.0%; the content of Cr is 25.0%; the content of Mo is 3.1%; the content of Ni is 7.8%; the content of RE is 0.1%; The ferrite content of ground stainless steel is 56.1%, the austenite content is 43.9%, and the precipitation hardening phase content after heat treatment is 8.2%.

Example 7

The difference between embodiment 7 and embodiment 1 is: a kind of wear-resistant stainless steel, which includes the following substances by mass percentage: C content is 0.06%; Si content is 0.8%; Mn content is 1.65%; P content is 0.030%; The content of Cu is 0.020%; the content of Cu is 2.0%; the content of Cr is 25.0%; the content of Mo is 3.1%; the content of Ni is 6.7%; the content of RE is 0.1%; The ferrite content of ground stainless steel is 58.5%, the austenite content is 41.5%, and the precipitation hardening phase content after heat treatment is 8.1%.

Example 8

The difference between embodiment 8 and embodiment 1 is: a kind of wear-resistant stainless steel, which includes the following substances by mass percentage: C content is 0.06%; Si content is 0.8%; Mn content is 2.45%; P content is 0.030%; The content of Cu is 0.020%; the content of Cu is 2.0%; the content of Cr is 25.0%; the content of Mo is 3.1%; the content of Ni is 6.7%; the content of RE is 0.1%; The ferrite content of ground stainless steel is 59.2%, the austenite content is 40.8%, and the precipitation hardening phase content after heat treatment is 8.2%.

Example 9

The difference between embodiment 9 and embodiment 1 is: a wear-resistant stainless steel, which includes the following substances in terms of mass percentage: C content is 0.06%; Si content is 0.8%; Mn content is 2.05%; P content is 0.030%; The content of Cu is 0.020%; the content of Cu is 2.0%; the content of Cr is 25.0%; the content of Mo is 3.1%; the content of Ni is 6.7%; the content of RE is 0.1%; The ferrite content of ground stainless steel is 60.8%, the austenite content is 39.2%, and the precipitation hardening phase content after heat treatment is 8.3%.

Example 10

The difference between Example 10 and Example 1 is: a wear-resistant stainless steel, which includes the following substances in terms of mass percentage: C content is 0.06%; Si content is 0.8%; Mn content is 2.05%; P content is 0.030%; S The content of Cu is 0.020%; the content of Cu is 2.4%; the content of Cr is 25.0%; the content of Mo is 3.1%; the content of Ni is 6.7%; the content of RE is 0.1%; The ferrite content of ground stainless steel is 63.1%, the austenite content is 36.9%, and the precipitation hardening phase content after heat treatment is 8.3%.

Example 11

The difference between Example 11 and Example 1 is: a wear-resistant stainless steel, which includes the following substances in terms of mass percentage: C content is 0.06%; Si content is 0.8%; Mn content is 2.05%; P content is 0.030%; S The content of Cu is 0.020%; the content of Cu is 2.2%; the content of Cr is 25.0%; the content of Mo is 3.1%; the content of Ni is 6.7%; the content of RE is 0.1%; The ferrite content of ground stainless steel is 61.1%, the austenite content is 38.9%, and the precipitation hardening phase content after heat treatment is 8.2%.

comparative example

Comparative example 1

The difference between Comparative Example 1 and Example 1 is: a wear-resistant stainless steel, which comprises the following substances by mass percentage: C content is 0.06%; Si content is 0.8%; Mn content is 1.65%; P content is 0.030%; The content of Cu is 0.020%; the content of Cu is 2.0%; the content of Cr is 22.0%; the content of Mo is 2.6%; the content of Ni is 5.5%; the content of RE is 0.1%; The ferrite content of ground stainless steel is 46%, the austenite content is 54%, and the precipitation hardening phase content after heat treatment is 7.2%.

Comparative example 2

The difference between Comparative Example 2 and Example 1 is: a wear-resistant stainless steel, which comprises the following substances by mass percentage: C content is 0.06%; Si content is 0.8%; Mn content is 1.65%; P content is 0.030%; The content of Cu is 0.020%; the content of Cu is 2.0%; the content of Cr is 28%; the content of Mo is 2.6%; the content of Ni is 5.5%; the content of RE is 0.1%; the balance is Fe and unavoidable impurities; The ferrite content of ground stainless steel is 72%, the austenite content is 28%, and the precipitation hardening phase content after heat treatment is 8.6%.

Comparative example 3

The difference between Comparative Example 3 and Example 1 is: a wear-resistant stainless steel, which comprises the following substances by mass percentage: C content is 0.06%; Si content is 0.8%; Mn content is 1.65%; P content is 0.030%; S The content of Cu is 0.020%; the content of Cu is 2.0%; the content of Cr is 24.2%; the content of Mo is 2.6%; the content of Ni is 3.0%; the content of RE is 0.1%; The ferrite content of ground stainless steel is 74%, the austenite content is 26%, and the precipitation hardening phase content after heat treatment is 8.3%.

Comparative example 4

The difference between Comparative Example 4 and Example 1 is: a wear-resistant stainless steel, which comprises the following substances by mass percentage: C content is 0.06%; Si content is 0.8%; Mn content is 1.65%; P content is 0.030%; S The content of Cu is 0.020%; the content of Cu is 2.0%; the content of Cr is 24.2%; the content of Mo is 2.6%; the content of Ni is 10.0%; the content of RE is 0.1%; The ferrite content of ground stainless steel is 43%, the austenite content is 57%, and the precipitation hardening phase content after heat treatment is 8.5%.

Comparative example 5

The difference between Comparative Example 5 and Example 1 is that no element RE is added.

Comparative example 6

The difference between Comparative Example 6 and Example 1 is: a wear-resistant stainless steel, which comprises the following substances by mass percentage: C content is 0.06%; Si content is 0.8%; Mn content is 1.65%; P content is 0.030%; S The content of Cu is 0.020%; the content of Cu is 1.0%; the content of Cr is 24.2%; the content of Mo is 2.6%; the content of Ni is 5.5%; the content of RE is 0.1%; The ferrite content of ground stainless steel is 54%, the austenite content is 46%, and the precipitation hardening phase content after heat treatment is 7.9%.

Comparative example 7

The difference between comparative example 7 and embodiment 1 is: a kind of wear-resistant stainless steel, which comprises the following substances by mass percentage: C content is 0.06%; Si content is 0.8%; Mn content is 1.65%; P content is 0.030%; The content of Cu is 0.020%; the content of Cu is 3.0%; the content of Cr is 24.2%; the content of Mo is 2.6%; the content of Ni is 10.0%; the content of RE is 0.1%; The ferrite content of ground stainless steel is 54%, the austenite content is 46%, and the precipitation hardening phase content after heat treatment is 7.9%.

performance test

Test 1:

1. Hardness after heat treatment: according to GB/T230.1-2018 "Metallic Materials. Rockwell Hardness Test Part 1: Test Method", the hardness after heat treatment of the products prepared in Examples 1-11 and Comparative Examples 1-5 The test, so as to detect the wear resistance of the product.

2. Corrosion resistance: According to JB/T7901-1999 "Metal Material Laboratory Uniform Corrosion Full Immersion Test Method", with a concentration of 10% sulfuric acid, the test temperature is 80 ° C, for examples 1-11 and comparative examples 1- 5 The prepared product is tested for corrosion resistance.

Combining Examples 1-5 and Comparative Examples 1-2 and Table 1, it can be seen that Cr is the main ferrite matrix element, in order to ensure that the ferrite matrix of the material is at 50%-70%, so that the resistance of stainless steel The corrosion performance and hardness are better, and when the content of Cr in Example 3 makes the ferrite in the best ratio, and Mo is a secondary element to form the ferrite matrix, adding Mo can obviously improve the corrosion resistance of the material, Taking into account the overall consideration, the content of elements Cr and Mo in Example 5 is the best.

In combination with Examples 6-9 and Comparative Examples 3-5 and in conjunction with Table 1, it can be seen that Ni is the main austenitic matrix element to form, and in order to ensure that the australite matrix is between 30%-50%, it is necessary to improve the corrosion resistance of acid performance, and improve the plasticity of the material, thereby improving the hardness of the material, the content of Ni is the best in Example 7, and Mn is a secondary element that forms the austenitic matrix element, and Mn cooperates with Ni to form the australoid matrix to improve the hardness of the material Cost performance, combined with comprehensive consideration, the content of elements Mn and Ni in Example 9 is the best; according to Comparative Example 5, it can be seen that the main function of RE is to increase the amount of austenite, refine the grain, and improve the comprehensive mechanical properties of stainless steel , especially to improve the hardness of stainless steel after heat treatment, and the plasticity of the material after the hardness of stainless steel is improved. .

In combination with Examples 10-11 and Comparative Examples 6-7 and in combination with Table 1, it can be seen that Cu can effectively improve the corrosion resistance of stainless steel. When the Cu content is less than 1.8%, the acid-resistant corrosion performance has a significant decline, while it is greater than 2.5%. %, the plasticity of the material after heat treatment will obviously deteriorate, resulting in a decrease in the hardness of the stainless steel, and the Cu content in Example 11 can make the corrosion resistance and hardness of the stainless steel better.

This specific embodiment is only an explanation of this application, and it is not a limitation of this application. Those skilled in the art can make modifications to this embodiment without creative contribution according to needs after reading this specification, but as long as the 77th paragraph of this application All claims are protected by patent law.

Claims (9)

1. A wear resistant stainless steel, characterized by: the wear-resistant stainless steel comprises the following substances in percentage by mass:

the content of C is below 0.08%;

si content is 1.0% or less;

mn content is 1.0% -3.0%;

the P content is below 0.035%;

s content is below 0.030%;

cu content is 1.5% -2.8%;

the Cr content is 23.0% -27.0%;

the Mo content is 2.0% -4.0%;

the Ni content is 4.0% -9.0%;

the balance of Fe and unavoidable impurities;

the microstructure is ferrite and austenite as matrix, and after heat treatment, the microstructure also contains precipitation hardening phase.

2. A wear resistant stainless steel according to claim 1, wherein: the wear-resistant stainless steel also comprises RE, and the RE content is below 0.10%.

3. A wear resistant stainless steel according to claim 1, wherein: the content of ferrite is 50% -70%, the content of austenite is 30% -50%, and the content of precipitation hardening phase after heat treatment is 5% -10%.

4. A wear resistant stainless steel according to claim 1, wherein: the Cr content is 24.0% -26.0%.

5. A wear resistant stainless steel according to claim 1, wherein: the Mo content is 2.5% -3.5%.

6. A wear resistant stainless steel according to claim 1, wherein: the Ni content is 5.0% -8.0%.

7. A wear resistant stainless steel according to claim 1, wherein: the Mn content is 1.5% -2.5%.

8. A wear resistant stainless steel according to claim 1, wherein: the Cu content is 1.8% -2.5%.

9. A process for the preparation of a wear resistant stainless steel according to any one of claims 1 to 8, characterized in that: the method comprises the following steps:

step 1: casting and forming a workpiece, namely melting Fe into molten iron at high temperature, adding C, si, mn, P, S, cu, cr, mo, ni and RE elements with accurate metering into the molten iron, uniformly mixing, casting into a mould, and cooling and forming to obtain the workpiece;

step 2: and (3) carrying out heat treatment on the workpiece, preheating a box-type electric furnace, placing the workpiece into the box-type electric furnace, heating the workpiece to 1000-1200 ℃, preserving heat for 2-3 hours, directly discharging the workpiece out of the furnace, cooling the workpiece with water for 30 seconds or less, feeding the cooled workpiece into the furnace again, directly heating to 790-830 ℃, preserving heat for 1-2 hours, discharging the workpiece out of the furnace, and cooling the workpiece to room temperature in the air to obtain the wear-resistant stainless steel.