摘要
通过对304及430不锈钢热轧板材焊接接头热影响区（HAZ）的金相观察、无损检测、显微硬度测定、力学性能和晶间腐蚀性能试验,研究经手工钨极氩弧焊（TIG）的304及430热轧板材的HAZ组织及性能,并进行对比分析.结果表明,采用TIG焊接方法和较小的焊接规范,304焊接接头的热影响区奥氏体晶粒较细（7.5-8.0级）,显微硬度为376 HV,焊缝与母材熔合良好;430焊接接头的热影响区铁素体晶粒明显长大（约为4.5级）,粗晶粒区宽度约为0.7 mm,碳化物析出不多;热影响区的晶界部位受焊接热循环影响发生了α→γ→M相变,生成的M质量分数约占14%;304和430焊接接头的力学性能良好,拉伸断裂部位是焊缝和热影响区;EPR法测定表明,304及430母材和热影响区均没有产生晶间腐蚀.
The microstructure and properties of heat-affected zone （HAZ） of welded joint on hot roiled 304 and 430 stainless steel sheets were studied through metallographic microscopy, nondestructive exami- nation （NDE）, microhardness test, mechanical property and intergranular attack test. The same investigation was made on the same weld with manual tungsten-inert-gas arc welding （TIG） ; and both were comparatively analyzed. The result showed that when TIG （arc） welding and less welding variables were adopted, the austenite crystal of HAZ of 304 did not grow up severely, a coarse grain zone being about 0.4 mm in size with grain size of 7.5-8. 0 grade, its microhardness was 376 HV; the fusion of interface of base material and welded seam was fine. The ferrite crystal of HAZ of 304 grew up remarkably, a coarse grain zone was about 0. 7 mm in size, its grain size was 4. 5 grade, carbides were not obviously precipitated, in the grain-boundary area of HAZ phase transformation α→γ→M took place, the martensite percentage was about 14%. Mechanical properties of welded joint of 304 and 430 were good, the position of tension fracture were located at welded seam and HAZ, respectively. It was shown by EPR test that base material and HAZ of 304 and 430 had no susceptibility to intergranular attack.
出处
《兰州理工大学学报》
CAS
北大核心
2009年第3期13-16,共4页
Journal of Lanzhou University of Technology
基金
甘肃省有色金属新材料重点实验室开放基金(SKL05011)的资助
关键词
不锈钢
TIG
热影响区
显微组织
stainless steel
TIG
heat-affected zone
microscopic structure
