ITER TF铠甲焊缝力学性能研究  

STUDY ON THE MECHANICAL PROPERTIES OF WELDING PART OF ITER TF JACKET

作　　者：金环[1] 武玉[1] 韩奇阳[1] 

机构地区：[1]中国科学院等离子体物理研究所,合肥230031

出　　处：《低温物理学报》2011年第1期25-29,共5页Low Temperature Physical Letters

基　　金：ITER超导导体及校正场线圈的设计与关键技术研究(批准号:2008GB101000))项目基金资助的课题~~

摘　　要：ITERTF线圈的CICC导体套管由316LN不锈钢管采用氩弧焊自熔对焊连接而成.选择三种不同的316LN不锈钢管为研究对象,它们分别为母材管、焊接未变形管和焊接后经过8%的冷作变形和650℃下200小时的老化处理的316LN不锈钢管,在室温下对这三种型号的不锈钢管进行拉伸试验,对前两种材料进行冲击试验,同时在4.2K下对焊接变形并经过老化处理的管子进行了拉伸试验,研究了母材与焊缝在室温和4.2K下的力学性能.采用SEM对拉伸断口形貌进行了观察,并采用金相显微镜对焊接未变形管的焊缝进行了观察.结果表明,断后伸长率、屈服强度、抗拉强度、杨氏模量均满足ITER要求,其中4.2K下屈服强度>950MPa,断后伸长率>20%.从拉伸断口形貌的扫描电镜图片可以看出,断口是由大量的韧窝组成,属韧性断裂.室温下焊接未变形管的冲击韧性与母材的相当,焊缝的塑韧性与母材的相当.The conduit of ITER TF coils′ CICC conductor was made of modified stainless steel 316LN（SS316LN）using TIG welded from the melting to connect.Three different 316LN stainless steel conduits were measured.They were base metal,weld metal and the weld metal after 8% cold deformation at 650℃ for 200 hours aging heat treatment.At room temperature tensile tests were conducted on these three kinds of stainless steel conduits,impact tests were conducted on the first two materials.At the same time the tensile test at 4.2K was conducted on the weld materials after 8% cold work at 650℃ for 200 hours aging heat treatment,the mechanical properties of base metal and welding part were studied at room temperature and 4.2K.The tensile fracture surfaces were observed by Scanning Electron Microscope （SEM）,and the welding part was observed by Metallographic Microscope.It was found that the elongation,yield strength （0.2% offset）,ultimate tensile strength and Young’s modulus were all satisfied the requirements of ITER.The yield strength is more than 950 MPa,and the elongation is more than 20% at 4.2K.The SEM images show the typical fracture surfaces of the tensile specimen.The dimples,which represent ductile failure.The impact strength of welded conduit is the same as the base metal at room temperature,so they had same plastic.

关 键 词：316LN不锈钢 冷变形 断后伸长率 屈服强度 冲击韧性 

分 类 号：TG407[金属学及工艺—焊接]