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以304奥氏体不锈钢为研究对象,采用高压扭转工艺对其性能进行改进。利用金相显微镜、显微硬度计和X射线衍射仪分析压力对304奥氏体不锈钢组织和性能的影响规律。结果表明,压力越大对基体组织晶粒剪切破碎越有利,晶粒细化及强化效果越明显。高压扭转前后材料内部位错密度由3.41×1014 m-2增加到5.07×1014 m-2,亚晶尺寸由59.54nm细化到46.03nm,细化程度达22.7%。高压扭转主要通过细晶引起晶粒滑移系位错源开动的阻碍作用来实现304奥氏体不锈钢强化。
With 304 austenitic stainless steel as the research object, its performance is improved by high-pressure torsion process. The influence of pressure on the microstructure and properties of 304 austenitic stainless steel was analyzed by metallographic microscope, microhardness tester and X-ray diffractometer. The results show that the bigger the pressure is, the more favorable the shearing and crushing of the crystal grains of the matrix is, the more obvious the grain refinement and strengthening effect is. The dislocation density increased from 3.41 × 1014 m-2 to 5.07 × 1014 m-2 before and after high-pressure torsion, and the subgrain size was refined from 59.54 nm to 46.03 nm with a degree of refinement of 22.7%. High-pressure torsion mainly through austenitic grain-slip system dislocation source to start the impediment to achieve 304 austenitic stainless steel strengthening.