时效析出相对铸造2507超级双相不锈钢力学及耐蚀性能的影响  

EFFECTS OF PRECIPITATION FOR AGING ON MECHANICAL AND CORROSION RESISTANCE PROPERTIES OF CAST 2507 SUPER DUPLEX STAINLESS STEEL

作　　者：向红亮[1] 刘东[1] 阮方如[1] 何福善[1] 黄利光[1] 

机构地区：[1]福州大学机械工程及自动化学院,福州350108

出　　处：《金属学报》2010年第8期941-945,共5页Acta Metallurgica Sinica

基　　金：科技部科技人员服务企业项目2009GJC40018;福建省青年人才创新基金项目2008F3061;福州大学科技发展基金项目2008-XQ-16资助~~

摘　　要：通过OM,SEM以及拉伸实验与电化学测试等手段,研究了高温时效析出金属间相对铸造2507超级双相不锈钢力学及耐蚀性能的影响.实验结果表明:材料固溶后经650—950℃时效处理,析出弥散颗粒χ相有提高抗拉强度的作用,σ相却使抗拉强度急剧下降;二者均使塑性急剧恶化,拉伸断口均表现为脆性断裂.在人工海水中,σ相对材料的耐蚀性影响要比χ相弱,其数量越多,材料耐蚀性越差.Duplex stainless steel（DSS） has been used widely due to its very excellent combination of mechanical and corrosion resistance properties.However,the use of DSS is limited by their susceptibility to the formation of dangerous intermetallic phases,such asσphase andχphase,resulting in the detrimental effects on mechanical properties and corrosion resistance.With the application of the super duplex stainless steel（SDSS） with a pitting resistance equivalent number more than 40. The harmful effects of intermetallic phases easily precipitated in DSS on mechanical properties and corrosion resistance are a research focus.This paper,based on prior study,investigates the effects of intermetallic phases formed during aging on the mechanical properties and corrosion resistance of cast 2507 super duplex stainless steel by means of optical microscope（OM）,scanning electron microscope （SEM）,tensile test and electrochemical test.The results indicate that for the solution annealing cast 2507 super duplex stainless steel aged in the temperature range 650—950℃,small and depressive distributionχphase precipitated from ferrite can increase its tensile strength,butσphase causes the opposing effect on its plasticity owing to precipitated along grain boundaries.Both of them can rapidly deteriorate its plasticity,and cause brittle failure.The effect ofσphase on corrosion resistance of 2507 SDSS is weaker thanχphase.The more theσphase is,the worse the corrosion resistant could be.

关 键 词：铸造2507超级双相不锈钢 金属间相 力学性能 耐蚀性 

分 类 号：TG172.8[金属学及工艺—金属表面处理]