阅读说明：本技术 一种301l不锈钢的制备方法 (Preparation method of 301L stainless steel ) 是由 石玉 喇培清 杨理洁 王乾隆 魏孔振 安宁 于 2019-09-19 设计创作，主要内容包括：本发明属于301L不锈钢制备技术领域。为了获得具有更高强度和硬度的301L不锈钢,本发明公开了一种301L不锈钢的制备方法,具体包括以下步骤：步骤S1,采用铝热反应制备获得301L不锈钢铸锭；步骤S2,对步骤S1中获得的301L不锈钢铸锭进行机械处理：首先对301L不锈钢铸锭进行热轧处理且热轧压下量为65％；接着进行第一次冷轧处理,每道次压下量为0.1mm,总的冷轧压下量为30％；然后进行第二次冷轧处理,每道次压下量为0.1mm,总的冷轧压下量为23％；步骤S3,对经过机械处理的301L不锈钢样件进行退火处理,获得最终的301L不锈钢。采用本发明的方法可以获得具有高强度和高硬度的301L不锈钢,满足对301L不锈钢的更高使用要求。(The invention belongs to the technical field of 301L stainless steel preparation. In order to obtain 301L stainless steel with higher strength and hardness, the invention discloses a preparation method of the 301L stainless steel, which specifically comprises the following steps: step S1, preparing and obtaining a 301L stainless steel ingot by adopting aluminothermic reaction; step S2, the 301L stainless steel ingot obtained in step S1 is mechanically processed: firstly, carrying out hot rolling treatment on a 301L stainless steel ingot, wherein the hot rolling reduction is 65%; then, carrying out first cold rolling treatment, wherein the reduction of each pass is 0.1mm, and the total cold rolling reduction is 30%; then, carrying out secondary cold rolling treatment, wherein the reduction of each pass is 0.1mm, and the total cold rolling reduction is 23%; step S3, annealing the mechanically processed 301L stainless steel sample to obtain the final 301L stainless steel. The method can obtain the 301L stainless steel with high strength and high hardness, and meets the higher use requirement of the 301L stainless steel.)

1. A preparation method of 301L stainless steel is characterized by comprising the following steps:

step S1, preparing and obtaining a 301L stainless steel ingot by adopting aluminothermic reaction;

step S2, the mechanical rolling process is performed on the 301L stainless steel ingot obtained in step S1:

firstly, carrying out hot rolling treatment on a 301L stainless steel ingot, wherein the hot rolling reduction is 65%;

then, carrying out first cold rolling treatment in a room temperature environment, wherein the reduction of each pass is 0.1mm, and the total cold rolling reduction is 30%;

then, carrying out secondary cold rolling treatment in a room temperature environment, wherein the reduction of each pass is 0.1mm, and the total cold rolling reduction is 23%;

in step S3, the 301L stainless steel sample mechanically processed in step S2 is annealed to obtain the final 301L stainless steel.

2. The method of claim 1, wherein in the step S1, the reaction raw materials for preparing the 301L stainless steel ingot comprise, by mass percent: 12-15% of Cr powder, 3-6% of Ni powder, 2-4% of Mn powder and Si₃N₄0.4 to 0.6 percent of powder, 17 to 19 percent of Al powder and the balance of Fe₂O₃And (3) powder.

3. The preparation method of claim 1, wherein in the step S1, the specific steps of preparing and obtaining a 301L stainless steel ingot by using the thermite reaction are as follows:

step S11, mixing the reaction raw materials, and pressing the mixed raw materials into a cake-shaped blank;

step S12, placing the blank into a combustion synthesis reaction kettle, and placing a detonator on the surface of the blank;

step S13, filling argon gas of 0.5MPa to 1MPa into the reaction kettle, keeping the pressure for 5min to 15min, then discharging the gas, and discharging the residual gas in the reaction kettle again when the temperature in the reaction kettle is heated to 110 ℃ to 130 ℃;

and step S14, filling argon into the reaction kettle again to increase the pressure in the reaction kettle to 4-6 MPa, and carrying out thermite reaction in the reaction kettle when the temperature in the reaction kettle is increased to 260-300 ℃ to prepare 301L stainless steel cast ingots.

4. The production method according to claim 1, wherein in the step S2, the 301L stainless steel ingot obtained in the step S1 is heated to 1200 ℃ to be subjected to hot rolling treatment.

5. The production method according to claim 4, wherein the solution treatment is performed in advance on the 301L stainless steel ingot obtained in step S1 at 1200 ℃ for 3 hours before the hot rolling treatment in step S2.

6. The manufacturing method according to claim 1, wherein in step S2, the 301L stainless steel sample subjected to the hot rolling process is subjected to acid pickling, annealing, and acid pickling in this order, and then subjected to the first cold rolling process.

7. The manufacturing method according to claim 1, wherein in the step S2, the 301L stainless steel sample subjected to the first cold rolling treatment is subjected to acid washing, annealing, and acid washing in this order, and then subjected to the second cold rolling treatment.

8. The method according to any one of claims 6 to 7, wherein 30% HNO by volume is selected₃3% HF and 67% H₂Pickling with O solutionAnd (6) processing.

9. The production method as set forth in any one of claims 6 to 7, wherein the 301L stainless steel sample subjected to the hot rolling treatment and the 301L stainless steel sample subjected to the first cold rolling treatment are annealed at 1140 ℃ for 2min, respectively.

10. The method according to claim 1, wherein in step S3, the mechanically treated 301L stainless steel sample is subjected to stress relief annealing at 408 ℃ for 2 hours.

Technical Field

The invention belongs to the technical field of stainless steel preparation, and particularly relates to a preparation method of 301L stainless steel.

Background

The rail vehicle is generally composed of a vehicle body, a frame, a power and transmission system and other auxiliary systems, wherein the vehicle body of the rail vehicle can be divided into a non-load-bearing vehicle body and a load-bearing vehicle body according to whether the vehicle body bears the load or not, and most of the rail vehicles adopt the load-bearing vehicle body at present, so that the rail vehicle is required to have stronger rigidity and deformation resistance.

Currently, the structural materials of the body of the railway vehicle mainly include weathering steel (or low alloy) high strength steel, aluminum alloy and stainless steel. Among them, stainless steel and aluminum alloy have characteristics such as light weight and better corrosion resistance than weathering steel, and therefore, both have already taken a leading position in the market. The maintenance cost can be greatly reduced for stainless steel car body structures in coastal areas (with moist air and rich in a large amount of chloride ions) and plateau areas and with good corrosion resistance in the running process of the car, and the method has higher market value. In addition to the requirements of the vehicle speed and the environment on the vehicle body, compared with the aluminum alloy vehicle body, (1) the stainless steel vehicle body has good corrosion resistance, the vehicle body structure does not need coating, the manufacturing time and the working procedure of a new vehicle are reduced, and meanwhile, the cost of later maintenance and repair of the vehicle body can be reduced; (2) the stainless steel material has high yield ratio and high elongation at break, so that the shock resistance of the vehicle body is good; (3) stainless steel is much more resistant to high temperatures than aluminum alloy, for example, when the body temperature reaches 500 ℃, the aluminum alloy door seals by exceeding the melting temperature. Compared with the aluminum alloy, the melting temperature of the stainless steel is 2.6 times that of the aluminum alloy, so that the safety and the service life of the stainless steel car body are greatly improved. The stainless steel car body is the most economical urban rail car body material at present after considering the influence of various factors comprehensively, and is used as a preparation material for most parts in the stainless steel car body of the rail car because the 301L stainless steel material can meet the requirement of light weight.

However, the hardness of the 301L stainless steel with the highest strength grade on the market is only about 200HV, the yield strength is only about 685MPa, and the tensile strength is only about 930MPa, so that the further wide application of the 301L stainless steel in the preparation of railway vehicles is restricted.

Disclosure of Invention

In order to obtain the 301L stainless steel with higher strength and hardness, the invention provides a preparation method of the 301L stainless steel, which is simple in preparation, low in cost and high in benefit, and the preparation method specifically comprises the following steps:

step S1, preparing and obtaining a 301L stainless steel ingot by adopting aluminothermic reaction;

step S2, the mechanical rolling process is performed on the 301L stainless steel ingot obtained in step S1:

firstly, carrying out hot rolling treatment on a 301L stainless steel ingot, wherein the hot rolling reduction is 65%;

then, carrying out first cold rolling treatment in a room temperature environment, wherein the reduction of each pass is 0.1mm, and the total cold rolling reduction is 30%;

then, carrying out secondary cold rolling treatment in a room temperature environment, wherein the reduction of each pass is 0.1mm, and the total cold rolling reduction is 23%;

in step S3, the 301L stainless steel sample mechanically processed in step S2 is annealed to obtain the final 301L stainless steel.

Preferably, in the step S1, the reaction raw materials for preparing 301L of the stainless steel ingot comprise, by mass: 12-15% of Cr powder, 3-6% of Ni powder, 2-4% of Mn powder and Si₃N₄0.4 to 0.6 percent of powder, 17 to 19 percent of Al powder and the balance of Fe₂O₃And (3) powder.

Preferably, in step S1, the preparation method for obtaining 301L of stainless steel ingot by thermite reaction includes the following steps:

step S11, mixing the reaction raw materials, and pressing the mixed raw materials into a cake-shaped blank;

step S12, placing the blank into a combustion synthesis reaction kettle, and placing a detonator on the surface of the blank;

step S13, filling argon gas of 0.5MPa to 1MPa into the reaction kettle, keeping the pressure for 5min to 15min, then discharging the gas, and discharging the residual gas in the reaction kettle again when the temperature in the reaction kettle is heated to 110 ℃ to 130 ℃;

and step S14, filling argon into the reaction kettle again to increase the pressure in the reaction kettle to 4-6 MPa, and carrying out thermite reaction in the reaction kettle when the temperature in the reaction kettle is increased to 260-300 ℃ to prepare 301L stainless steel cast ingots.

Preferably, in the step S2, the 301L stainless steel ingot obtained in the step S1 is heated to 1200 ℃ to be hot rolled.

Further preferably, the 301L stainless steel ingot obtained in step S1 is subjected to solution treatment at 1200 ℃ for 3 hours before the hot rolling treatment in step S2.

Preferably, in the step S2, the 301L stainless steel sample after the hot rolling process is sequentially subjected to acid pickling, annealing, and acid pickling, and then subjected to the first cold rolling process.

Preferably, in step S2, the 301L stainless steel sample after the first cold rolling is subjected to acid washing, annealing, and acid washing in this order, and then subjected to the second cold rolling.

Further preferably, 30% by volume of HNO is selected₃3% HF and 67% H₂And carrying out acid washing treatment on the solution of O.

Further preferably, the 301L stainless steel sample after the hot rolling treatment and the 301L stainless steel sample after the first cold rolling treatment are annealed at 1140 ℃ for 2 min.

Preferably, in the step S3, the mechanically processed 301L stainless steel sample is subjected to stress relief annealing treatment at 408 ℃ for 2 hours.

The invention has the following beneficial technical effects:

1. by adopting the method, the 301L stainless steel cast ingot is prepared and obtained through the aluminothermic reaction with low cost, and the 301L stainless steel with high mechanical property and high economic added value can be obtained through one hot rolling mechanical treatment and two cold rolling mechanical treatments under specific conditions, so that the problem that the 301L stainless steel with the highest strength level in the prior art is low in strength and hardness is solved, and the use requirements of the 301L stainless steel in the working condition environment with high strength and high hardness are met.

2. In the preparation process, the mechanical treatment process of the 301L stainless steel is accurately controlled, namely, the hot rolling treatment is firstly carried out at 1200 ℃, the hot rolling amount is controlled to be 65%, then the cold rolling treatment is respectively carried out twice, and the cold rolling amount of the two times is respectively controlled to be 30% and 23%, so that the effective effect of greatly improving the strength and the hardness of the 301L stainless steel is obtained, and the mechanical property requirements of the 301L stainless steel on high strength and high hardness are met.

Drawings

FIG. 1 is a schematic flow diagram of a process for making 301L stainless steel using the method of example 1.

Detailed Description

The technical solution of the present invention will be described in detail with reference to the accompanying drawings and specific embodiments.