摘要
利用XRD、SEM、TEM、EDS、金相显微镜、拉伸试验等方法研究了15-5PH不锈钢经400℃长期时效后组织及力学性能。随着时效时间延长,板条状马氏体逐渐变得细小,发生Spinodal分解,分解为富Cr相及富Fe相;大量ε-Cu相呈弥散析出;逆变奥氏体的量逐渐增多;粗大的析出相沿板条马氏体晶界分布;未溶解的NbC颗粒逐渐长大。随着时效时间的延长,抗拉强度先升高后下降,在1 000 h时达到最大值1 554 MPa;伸长率先下降后上升,在1 000 h时下降到最小值4.8%;断面收缩率逐渐减小,试样断裂方式由韧性断裂向脆性断裂转变。
The microstructure, phase and mechanical properties of 15-5PH stainless steel long-term aged at 400℃ were studied by XRD, SEM, TEM, EDS, metallographic microscope and tension test, etc. As the aging process proceeded, the lath martensite becomes finer, and spinodaly decomposes into Cr-rich phase and Fe-rich phase, a large number of ε-Cu phase disperse precipitates, the amount of reversed austenite increases gradually;massive precipitate distributes on the lath martensite grain boundary, undissolved NbC grains grow up gradually. As the aging process proceeded ,the tensile strength increases firstly then decreases, and reaches the peak value of 1 554 MPa at 1 000 hours, the elongation value decreases firstly then increases,and reduces to the minimum value of 4. 8% at 1 000 hours. The reduction of area decreases gradually, and the fracture mechanisms of the specimens are transformed from ductile fracture to brittle fracture.
出处
《失效分析与预防》
2013年第6期331-336,355,共7页
Failure Analysis and Prevention
基金
国家"863"计划资助项目(2012AA03A507)
江西省金属材料微结构调控重点实验室项目(JW201223001)
关键词
15-5PH不锈钢
时效
组织
力学性能
15-5PH stainless steel
aging
microstructure
mechanical property
