冷变形是提高奥氏体不锈钢强度的有效手段。本文以一种含氮量达1.0wt.%的高氮奥氏体不锈钢和316L不锈钢为研究对象，通过在室温下对这两种材料施加不同的压缩变形量，研究了两种材料变形后的显微组织、真应力-应变曲线、显微硬度。结果表明，两种材料在冷变形量小于20%时，机械孪晶和滑移共同参与变形。随变形量增加至50%，316L的变形方式过渡到以滑移为主，而高氮钢中机械孪晶和滑移仍共同参与变形。高氮奥氏体不锈钢在变形过程中不发生马氏体相变，表明其具有较高的结构稳定性，而316L中有马氏体形成。高氮不锈钢的固溶态强度、硬度和加工硬化系数均显著高于316L，冷变形可大幅提高两种材料的强度。两种材料的显微硬度均与晶粒取向有明显相关性，晶粒取向对显微硬度的影响大于变形的不均匀性。本文还对高氮不锈钢表现出的优异性能的机制进行了分析和讨论。
Cold deformation can effectively enhance the strength of austenitic stainless steels. In this paper, a high nitrogen austenitic stainless steel with 1.0wt.% nitrogen and the 316L stainless steel were investigated on their microstructures, true stress-strain curves and micro-hardness after compressive deformation at room temperature. It was found that both the mechanical twins and the slips participated in the deformation for both two steels under the deformation less than 20%, but the slips turned to be dominant for 316L when the deformation was increased to 50%, the high nitrogen steel still remaining the above two mechanisms. There was no α’ martensite transformation in the high nitrogen steel under deformation, showing better structure stability, but there was martensite in the 316L. The strength, the micro-hardness and the work-hardening effect of the high nitrogen steel were much higher than those of the 316L, and the strength could be largely enhanced by cold deformation for the two steels. The micro-hardness was related to the crystal orientation for the two steels and the effect of crystal orientation was larger than that of the microstructure inhomogeneity. The mechanism of the high nitrogen stainless steel showing excellent properties was also analyzed and discussed.
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