TTS444铁素体不锈钢焊接性及其接头缝隙腐蚀  

Weldability of TTS444 ferritic stainless steel and crevice corrosion of its welded joints

作　　者：张心保[1] 连杰[1] 王红鸿[2] 

机构地区：[1]山西太钢不锈钢股份有限公司技术中心,太原市030003 [2]武汉科技大学国际钢铁研究院,430081

出　　处：《焊接》2013年第7期32-34,70-71,共3页Welding & Joining

摘　　要：TTS444不锈钢是国内近年来开发的一种综合性能优良的超纯(C+N≤0.02%)铁素体不锈钢,其成分与性能对应于国外S44400牌号铁素体不锈钢。分析了该不锈钢的焊接性,并介绍在实际应用过程中由于焊接工艺设计失误造成的焊缝发生缝隙腐蚀失效案例,阐明了腐蚀产生的原因是由于焊接工艺设计不当形成了产生缝隙腐蚀的客观条件,TIG焊接接头在腐蚀介质作用下经过一段时间后发生点蚀,然后扩展为成片的缝隙腐蚀。分析表明,尽管TTS444超纯铁素体不锈钢具有很高的耐点蚀性能和良好的焊接性,但在实际应用中也不能完全依赖高耐蚀性来避免腐蚀的发生,而忽视接头设计和焊接工艺的影响;用E310L焊丝将蚀坑修补,并将接头缝隙填充,消除缝隙腐蚀产生条件,即可避免产生腐蚀现象。TTS444 stainless steel is a grade of hyper pure(C+N≤0.02%) ferritic stainless steel with excellent comprehensive properties developed in China recently,which is in accordance with abroad grade S44400 stainless steej.Weldability of TTS444 stainless steel was analyzed,and a crevice corrosion failure case of welded joints caused by improper welding procedure design was introduced.It is concluded that the inappropriate welding procedure design presents objective conditions for occurrence of crevice corrosion,and the pitting corrosion occurs in corrosive agent then expands to continuous crevice corrosion.It also reveals that the corrosion cannot be avoided in applications only by its high corrosion resistance although TTS444 stainless steel has high corrosion resistance,while the joint design and welding procedures play important roles in.corrosion resistance.The corrosion zone was repaired with E310L wire,and the fitting gap was filled up to eliminate condition of corrosion,hence the crevice corrosion can be prevented.

关 键 词：TTS444 铁素体不锈钢 焊接 缝隙腐蚀 

分 类 号：TG44[金属学及工艺—焊接]