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对304不锈钢进行了压缩变形实验,得到了不同变形速率下的真应力—应变曲线。结果显示,304不锈钢在室温到250℃下变形时,具有应变强化特性。在相同的压缩变形速率下,温度越高,冷变形形变强化作用越弱;在相同的温度下,压缩变形速率越大,冷变形形变强化作用越强。压缩和拉伸都能使试样的强度和硬度得到较大程度的提高。观察变形前后试样的金相图可知,冷变形后晶粒在一定程度上纤维化,并且由于位错密度的增加,在原来晶粒内部产生亚晶界,进一步发展为晶界,使晶粒细化。
The compressive deformation of 304 stainless steel was tested and the true stress-strain curve under different deformation rates was obtained. The results show that 304 stainless steel with strain hardening properties at room temperature to 250 ℃ deformation. Under the same compressive deformation rate, the higher the temperature, the weaker the cold deformation deformation strengthening effect; the greater the compression deformation rate, the stronger the cold deformation deformation strengthening effect at the same temperature. Compression and stretching can make the strength and hardness of the sample be greatly improved. Metallographic examination of the samples before and after deformation shows that the grains are fibrillated to a certain degree after cold deformation and due to the increase in dislocation density, subgrain boundaries are formed in the original grains and the grains further develop into grain boundaries, Refine.