焊后热处理对Q460钢焊缝组织及冲击性能的影响  

Effect of post weld heat treatment on microstructure and impact property of weld metal for Q460 steel

作　　者：肖红军[1] 田志凌[1] 崔冰[2] 江卓俊 

机构地区：[1]钢铁研究总院先进钢铁流程及材料国家重点实验室,北京100081 [2]安徽工业大学材料科学与工程学院,安徽马鞍山243000

出　　处：《金属热处理》2017年第10期11-15,共5页Heat Treatment of Metals

基　　金：国家国际科技合作专项(2015DFA51460)

摘　　要：采用光学金相显微镜、扫描电镜、透射电镜、背散射电子显微镜及力学性能测试等方法,对焊态及热处理态焊接接头的微观组织及冲击性能进行研究。结果表明,热处理后焊缝组织中的M-A组元已基本消失而且晶粒有长大现象。焊缝金属中的块状铁素体的增加、大角度晶界密度及尺寸小于2μm的有效晶粒所占比例由78.3%和72.9%下降为74.2%和61.8%是导致其韧性降低的原因。The weld metal microstructure and impact property of welded and post weld heat treatment（ PWHT） Q460 steel used in nuclear power were investigated by means of optical microscopy,scanning electron microscope,transmission electron microscopy and electron backscattered diffraction. The results show that M-A constituent in weld metal microstructure after PWHT is basically disappears and the grains grow up. The reason for the reduction of toughness includes the increased amount of blocky ferrite in weld metal microstructure,and the reduction of both the high angle boundary density（ from 78. 3% to 74. 2%） and the fraction of the effective grain whose size is smaller than2 μm（ from 72. 9% to 61. 8%） after the heat treatment.

关 键 词：Q460钢 焊后热处理 焊缝金属 大角度晶界 冲击性能 

分 类 号：TG142.1[一般工业技术—材料科学与工程]