阅读说明：本技术 一种超高强度和塑性304不锈钢的制备方法 (Preparation method of ultrahigh-strength and plastic 304 stainless steel ) 是由 喇培清 李正宁 郑月红 毛宇奇 盛捷 朱敏 占发琦 石玉 卜哲涵 杨江仁 杜明宸 于 2020-07-09 设计创作，主要内容包括：本发明属于304不锈钢的制备技术领域。为了获得具备高强度和塑性的304不锈钢,本发明提出了一种制备超高强度和塑性304不锈钢的方法。该超高强度和塑性304不锈钢的制备方法,具体包括以下步骤：步骤S1,秤取反应原料；反应原料包括Fe<Sub>2</Sub>O<Sub>3</Sub>粉末、Al粉末、Cr粉末、Si粉末、Mn粉末、Ni粉末以及C粉末；步骤S2,对反应原料进行混合处理,并对混合后的反应原料进行加压处理,获得坯体；步骤S3,进行铝热反应,制备304不锈钢铸锭。步骤S4,对获得的304不锈钢铸锭进行轧制量为50％的轧制和温度为700℃、时间为0.5～2h的退火处理,得到超高强度和塑性的304不锈钢。采用本发明的方法不仅可以制备获得超高强度和塑性的304不锈钢,而且可以降低制造成本,提高生产效率。(The invention belongs to the technical field of preparation of 304 stainless steel. In order to obtain 304 stainless steel with high strength and plasticity, the invention provides a method for preparing the ultrahigh-strength and plastic 304 stainless steel. The preparation method of the ultrahigh-strength and plastic 304 stainless steel specifically comprises the following steps: step S1, weighing reaction raw materials; the reaction raw material comprises Fe 2 O 3 Powder, Al powder, Cr powder, Si powder, Mn powder, Ni powder, and C powder; step S2, mixing the reaction raw materials, and pressurizing the mixed reaction raw materials to obtain a blank; and step S3, carrying out aluminothermic reaction to prepare 304 stainless steel ingot. And step S4, rolling the obtained 304 stainless steel ingot at a rolling amount of 50% and annealing at 700 ℃ for 0.5-2 h to obtain the ultrahigh-strength and plastic 304 stainless steel. The method of the invention not only can prepare the 304 stainless steel with ultrahigh strength and plasticity, but also can reduce the manufacturing cost and improve the production efficiency.)

1. A preparation method of an ultrahigh-strength and plastic 304 stainless steel is characterized by comprising the following steps:

step S1, weighing reaction raw materials; the reaction raw material comprises Fe by mass percent₂O₃64-65% of powder, 20-21% of Al powder, 10-12% of Cr powder, 0.5-0.7% of Si powder, 1.1-1.3% of Mn powder, 5-6% of Ni powder and 0.04-0.06% of C powder;

step S2, mixing the reaction raw materials, and pressurizing the mixed reaction raw materials to obtain a round cake-shaped blank;

step S3, firstly, placing the blank into a combustion synthesis reaction kettle, and placing an ignition agent on the upper surface of the blank; then, filling argon gas of 0.5MPa into the reaction kettle, starting heating, and discharging gas from the reaction kettle when the temperature in the reaction kettle is heated to 200 ℃; then filling 4MPa argon into the reaction kettle again and continuing to heat, and carrying out aluminothermic reaction in the reaction kettle when the temperature in the reaction kettle is heated to 260 ℃; finally, after the thermite reaction is finished and the temperature is cooled to the room temperature, a 304 stainless steel ingot is obtained;

step S4, rolling and annealing the obtained 304 stainless steel ingot to obtain ultrahigh-strength and plastic 304 stainless steel; wherein the rolling deformation is 50%, the annealing temperature is 700 ℃, and the annealing time is 0.5-2 h.

2. A method of manufacturing an ultra-high strength and plastic 304 stainless steel according to claim 1, wherein in the step S4, the 304 stainless steel ingot obtained in the step S3 is annealed for 1 h.

3. A method for manufacturing an ultra-high strength and plastic 304 stainless steel according to claim 1, wherein in the step S2, the reaction raw materials are first mixed by means of a QM-1SP4 planetary ball mill, wherein the rotation speed of the ball mill is set to 150r/min, and the ball-to-material ratio is set to 2: 1, mixing for 8 hours, changing the steering direction of a ball mill every 2 hours to ensure uniform mixing of reaction raw materials, and then placing the uniformly mixed reaction materials on a Y32-100t hydraulic press to press the materials into round cake-shaped blanks.

4. A method of manufacturing an ultra-high strength and plastic 304 stainless steel according to claim 1, wherein in the step S2, the reaction raw material is green-pressed using a pressure of 15MPa to 45 MPa.

5. The method for preparing an ultra-high strength and plastic 304 stainless steel as claimed in claim 1, wherein in the step S4, a two-roll hot-cold rolling mill is selected for rolling, and the rolling speed is 17r/min, the rolling speed is 0.2-0.6 m/S, and the reduction per rolling is 5%.

6. A method of manufacturing an ultra-high strength and plastic 304 stainless steel according to claim 1, wherein in the step S4, the 304 stainless steel ingot obtained in the step S3 is first subjected to a grinding and smoothing process of upper and lower surfaces and then to a rolling process.

Technical Field

The invention belongs to the technical field of preparation of 304 stainless steel, and particularly relates to a preparation method of ultrahigh-strength and plastic 304 stainless steel.

Background

The 304 stainless steel is a very important corrosion-resistant engineering material, and simultaneously has good plasticity because the microstructure of the 304 stainless steel is austenite at room temperature due to the existence of Cr and Ni elements. However, the relatively low strength of 304 stainless steel limits its application to important structures, but the strength thereof is greatly improved by increasing the number of defects due to the martensite structure obtained by cold deformation, and thus low-temperature deformation of 304 stainless steel has recently been receiving much attention in the fields of low-temperature traffic materials, liquefied natural gas, low-temperature technology, marine technology, food processing, and the like.

However, when the 304 stainless steel is deformed at low temperature or even below zero, a large amount of strain-induced martensite, twin crystals, stacking faults and high-density dislocations occur in an austenite structure, so that high strength is obtained, plasticity is lost, plasticity is greatly reduced, application and popularization of the 304 stainless steel in a plasticity requirement environment are limited, and the strength and plasticity of the 304 stainless steel cannot be guaranteed.

Disclosure of Invention

In order to obtain 304 stainless steel with high strength and plasticity, the invention provides a method for preparing 304 stainless steel with ultrahigh strength and plasticity, which comprises the following steps:

step S1, weighing reaction raw materials; the reaction raw material comprises Fe by mass percent₂O₃64-65% of powder, 20-21% of Al powder, 10-12% of Cr powder, 0.5-0.7% of Si powder, 1.1-1.3% of Mn powder, 5-6% of Ni powder and 0.04-0.06% of C powder;

step S2, mixing the reaction raw materials, and pressurizing the mixed reaction raw materials to obtain a round cake-shaped blank;

step S3, firstly, placing the blank into a combustion synthesis reaction kettle, and placing an ignition agent on the upper surface of the blank; then, filling argon gas of 0.5MPa into the reaction kettle, starting heating, and discharging gas from the reaction kettle when the temperature in the reaction kettle is heated to 200 ℃; then filling 4MPa argon into the reaction kettle again and continuing to heat, and carrying out aluminothermic reaction in the reaction kettle when the temperature in the reaction kettle is heated to 260 ℃; finally, after the thermite reaction is finished and the temperature is cooled to the room temperature, a 304 stainless steel ingot is obtained;

step S4, rolling and annealing the obtained 304 stainless steel ingot to obtain ultrahigh-strength and plastic 304 stainless steel; wherein the rolling deformation is 50%, the annealing temperature is 700 ℃, and the annealing time is 0.5-2 h.

Preferably, in the step S4, the 304 stainless steel ingot obtained in the step S3 is annealed for 1 hour.

Preferably, in the step S2, the reaction raw materials are first mixed by means of a QM-1SP4 planetary ball mill, wherein the rotation speed of the ball mill is set to 150r/min, and the ball-to-material ratio is set to 2: 1, mixing for 8 hours, changing the steering direction of a ball mill every 2 hours to ensure uniform mixing of reaction raw materials, and then placing the uniformly mixed reaction materials on a Y32-100t hydraulic press to press the materials into round cake-shaped blanks.

Preferably, in the step S2, the reaction raw material is green-pressed by using a pressure of 15MPa to 45 MPa.

Preferably, in the step S4, a two-roll hot-cold rolling mill is selected for rolling, the rotation speed of the rolls is 17r/min, the rolling speed is 0.2 to 0.6m/S, and the reduction of each rolling is 5%.

Preferably, in the step S4, the 304 stainless steel ingot obtained in the step S3 is first subjected to a grinding and smoothing process of the upper and lower surfaces, and then to a rolling process.

In the method of the invention, low-cost Fe is selected₂O₃The high-strength and high-plasticity 304 stainless steel is prepared by the steps of preparing 304 stainless steel ingots through low-cost and low-energy-consumption aluminothermic reaction, and sequentially performing rolling treatment on the 304 stainless steel ingots by 50% in rolling quantity and annealing treatment at the annealing temperature of 700 ℃ and the annealing time of 0.5-2 h to obtain the ultrahigh-strength and high-plasticity 304 stainless steel. Therefore, the 304 stainless steel can be prepared by the method with low cost and low energy consumption, the cost for preparing the 304 stainless steel with ultrahigh strength and plasticity is reduced, the efficiency for preparing the 304 stainless steel is improved, the 304 stainless steel with ultrahigh strength and plasticity is obtained, and the popularization and application of the 304 stainless steel in different fields are met.

Drawings

Figure 1 is a schematic flow diagram of the process for making an ultra-high strength and plastic 304 stainless steel 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.