固溶处理对S32001双相不锈钢力学性能和点蚀敏感性影响  

Effect of Solid Solution Treatment on Mechanical Properties and Pitting Susceptibility of S32001 Duplex Stainless Steel

作　　者：施斌卿 胡涌玉 刘小钪 刘厚陶 吴劢 林鸿亮 王长罡[3] SHI Binqing;HU Yongyu;LIU Xiaokang;LIU Houtao;WU Mai;LIN Hongliang;WANG Changgang(School of Materials and Energy,Foshan University,Guangdong Foshan 528300,China;Guangqing Research Institute,Guangdong Yangjiang 529500,China;Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China)

机构地区：[1]佛山大学材料与能源学院,广东佛山528300 [2]广东广青金属科技有限公司,广东阳江529500 [3]中国科学院金属研究所,沈阳110016

出　　处：《装备环境工程》2024年第11期130-137,共8页Equipment Environmental Engineering

基　　金：国家自然科学基金(52373322);阳江市合金材料与五金刀剪重点产业人才振兴计划专项企业科技特派员项目(RCZX2022022);广东省高品质不锈钢技术研发企业重点实验室项目(2023B1212070017);阳江市科技计划省重点实验室资助项目(RCZX2023011)。

摘　　要：目的 研究固溶工艺对S32001经济型双相不锈钢的微观组织、拉伸力学性能和点蚀敏感性的影响作用。方法 通过光学显微镜、扫描电镜及EDS等方法,研究S32001双相不锈钢中的双相组织、固溶元素含量及腐蚀形貌。通过万能试验机研究拉伸力学性能随固溶工艺的变化规律,采用电化学工作站研究临界点蚀电位和临界点蚀温度等与固溶工艺的变化关系。结果 当固溶温度在1 000~1 200℃时,随着固溶温度的升高,铁素体相比例逐渐增加,而奥氏体相比例逐渐减小。屈服强度变化很小,而抗拉强度、断裂伸长率及强塑积等性能呈现逐渐减小的趋势。临界点蚀电位和临界点蚀温度等结果均表明,随着固溶温度的升高,不锈钢的点蚀敏感性呈现先减小、后增大的趋势。结论 S32001双相钢在不同固溶温度下的力学性能差异应主要与应变硬化行为有关,这主要与较高固溶温度下相变诱导塑性(TRIP效应)被抑制有关。当固溶温度为1 100℃时,奥氏体铁素体两相的体积比约1︰1,此时奥氏体相和铁素体相的耐点蚀当量(PREN值)最为接近,合金的点蚀敏感性最低,即抗点蚀能力最强。The work aims to study the effect ofsolid solution treatment on the microstructure,mechanical properties and pit-ting susceptibility of S32001 economical duplex stainless steel.The dual phase structure,solid solution element content and corrosion morphology of S32001 economic duplex stainless steel were studied by opticalmicroscope,scanning electron micro-scope,EDS,etc.Thevariation of tensile mechanical propertiesunder different solution treatment conditions wastested by univer-sal testing machine.The dependence of critical pitting potential and critical pitting temperature on solution treatment was stud-ied by electrochemical polarization test.At higher solid solution temperature in the range of 1000-1200℃,the proportion of ferrite phase increased gradually and the proportion of austenite phase decreased gradually with the increase of the solution temperature.The yield strength changed very little.As a result,the tensile strength,elongation-to-failure and strength-ductility balance showed a decreasing trend.Meanwhile,the results of electrochemical tests such as critical pitting potential and critical pitting temperature showed that the pitting susceptibility of stainless steel decreased first and then increased with the increase of solution temperature.The difference in the mechanical properties of S32001 duplex steel at different solution temperature could be mainly related to strain hardening behavior,due to the inhibition of phase transformation induced plasticity(TRIP)effect at higher solution temperature.When the solution temperature is 1100℃,the proportion of austenite and ferrite is about 1.Resultantly,the pitting resistance equivalent(PREN value)of austenite phase and ferrite phase is the closest,and the pitting sensitivity of the alloy is the lowest,that is,the pitting resistance is the strongest.

关 键 词：S32001双相不锈钢 固溶处理 点蚀敏感性 力学性能 TRIP效应 

分 类 号：TG142.2[一般工业技术—材料科学与工程] TG156.94[金属学及工艺—金属材料]