Effect of Aging Temperature on Microstructure and Mechanical Properties of Steel 0Cr17Ni4Cu4Nb

Based on 0Cr17Ni4Cu4 Nb martensite precipitation hardening stainless steel,the effect of aging temperature on the microstructure and mechanical properties was analyzed and the fracture feature of sample was observed.The experimental results indicate that as the aging temperature goes up(480-550℃),the tensile strengthσband the yield strengthσp0.2show the tendency of gradually decreasing,while the fracture shrinkageΨand elongation rateδ5exhibit the tendency of gradually increasing;the impact toughness akuis affected obviously by the aging temperature,is gradually increasing,among which,at 550℃,akureaches 213.4(J·cm-2).While,the analysis results from fracture observation show that when the aging temperature is at 550℃,the radiation zone of tensile fracture is the minimum,the plasticity is the best;impact fracture plastic deformation is most obvious,the shear lip zone and fibrous zone occupy the largest proportion.For 0Cr17Ni4Cu4 Nb stainless steel,as the aging temperature rises,quenching martensite matrix begins to restore,recrystallize,reverse austensite starts to form and grow,resulting in the increase of content of residual austenite,while the existing of residual austenite is conducive to maintain excellent plastic property and the toughness.