Nb微合金化对Cr-Co-Ni-Mo系超高强度不锈钢腐蚀疲劳性能的影响
Effect of Niobium Alloying on the Corrosion Fatigue Properties of the Cr-Co-Ni-Mo Series of Ultra-high Strength Stainless Steels
田帅 1张雪凌 2刘振宝 1王晓辉 1王长军 1孙永庆 1杨志勇 1齐越3
作者信息
- 1. 钢铁研究总院有限公司特殊钢研究院,北京 100081
- 2. 钢研纳克检测技术股份有限公司,北京 100081
- 3. 抚顺特殊钢股份有限公司技术中心,抚顺 113001
- 折叠
摘要
为探讨超高强度不锈钢的应力腐蚀开裂行为,采用Cr-Co-Ni-Mo系超高强度不锈钢为研究对象,利用OM、XRD、TEM等测试手段,结合腐蚀疲劳试验,研究了Nb微合金化对Cr-Co-Ni-Mo系超高强度不锈钢腐蚀疲劳性能的影响.结果表明,试验钢在3.5%NaCl溶液中具有一定的应力腐蚀敏感性,其应力腐蚀开裂机理为氢致开裂和阳极溶解的混合机制.Nb微合金化提高了钢的腐蚀疲劳性能,钢中添加0.11%的Nb后,钢的腐蚀疲劳强度由440 MPa提高至495 MPa,其主要原因是,Nb微合金化可以细化钢的晶粒尺寸,促进钢中不可逆氢陷阱NbC的析出,增加了钢中原奥氏体晶界总量、小角晶界所占比例、Σ3晶界数量、奥氏体体积分数等.
Abstract
In order to investigate the stress corrosion cracking behavior of ultra-high strength stainless steel,the influence of Nb microalloying on the corrosion fatigue properties of Cr-Co-Ni-Mo series ultra-high strength stainless steel was studied by OM,XRD,TEM and other testing methods in combination with corrosion fatigue test.The results show that the steel has stress corrosion sensitivity in 3.5%NaCl solution,and the stress corrosion cracking mechanism of the steel was a mixed mechanism involving hydrogen embrittlement and anodic dissolution.Niobium alloying improved the corrosion fa-tigue performance of the steel,that is,the corrosion fatigue strength of steel increases from 440 MPa to 495 MPa after add-ing 0.11%Nb.The main reason is that niobium alloying refined the grain size of steel,promoted the precipitation of irre-versible hydrogen trap of NbC in steel,and increased the amount of prior austenite grain boundaries,the proportion of low-angle grain boundaries,the number of Σ3 grain boundaries,and the volume fraction of austenite in steel.
关键词
超高强度不锈钢/腐蚀疲劳/应力腐蚀开裂机理/NbC/奥氏体Key words
Ultra-high Strength Stainless Steels/Erosion Fatigue/Mechanism of Stress Corrosion Cracking/NbC/Aus-tenite引用本文复制引用
出版年
2024
NETL
NSTL
维普
万方数据