焊接热输入对Q345R钢接头湿硫化氢应力腐蚀敏感性的影响  

Effect of Welding Heat Input on Microstructure and Stress Corrosion Sensitivity to Wet Hydrogen Sulfide of Welded Joints of Q345R Steel

作　　者：肖蒙[1] 张玮[1,2] 郑三龙[1,2] 黄六一 陈冰冰[1,2] 

机构地区：[1]浙江工业大学机械工程学院,浙江杭州310032 [2]浙江工业大学过程装备及其再制造教育部工程研究中心,浙江杭州310032 [3]浙江省特种设备检验研究院,浙江杭州310015

出　　处：《材料保护》2015年第4期33-35,7-8,共3页Materials Protection

基　　金：国家科技支撑计划课题(2011BAK06B02-03);浙江省质监系统科研计划项目(20130231)资助

摘　　要：实际焊接过程中焊接参数会影响焊接热输入,进而影响焊接接头的显微组织和性能。为此,研究了一系列焊接热输入条件下Q345R钢焊接接头的显微组织及其在湿硫化氢环境中的应力腐蚀敏感性。结果表明:当焊接热输入从44.2 k J/cm增加到49.7 k J/cm时,铁素体晶粒增大;当焊接热输入达到55.3 k J/cm时,焊缝区组织出现了针状铁素体;在湿硫化氢环境下慢应变速率拉伸,所有焊接热输入下的焊接接头均出现明显的应力腐蚀开裂,同时发现在相同浓度的湿硫化氢环境下,当焊接热输入从44.2 k J/cm增加到49.7 k J/cm时,焊接接头的应力腐蚀敏感性指数随之增大,当焊接热输入增大到55.3 k J/cm时,由于焊缝区出现了针状铁素体,使其应力腐蚀敏感性得到缓解。Microstructure and stress corrosion sensitivity to wet hydrogen sulfide of the welded joints of Q345 R steel under different welding heat inputs were analyzed.It was found that,when the welding heat input increased from 44.2 kJ/cm to 49.7 kJ/cm,the ferrite grain size increased.When the welding heat input reached 55.3 kJ/cm,acicular ferrite microstructure emerged in the welded zone.During slow strain rate tensile test in wet hydrogen sulfide environment,the welded joint underwent obvious stress corrosion cracking under all welding heat inputs.As the welding heat input increased from 44.2 kJ/cm to 49.7 kj/cm under the same concentration of wet hydrogen sulfide,the stress corrosion sensitivity index of the welded joints tended to increase therewith.As the welding heat input reached 55.3 kj/cm,the stress corrosion susceptibility of the welded joint was reduced owing to the emergence of acicular ferrite in the welded zone.

关 键 词：Q345R钢 焊接接头 焊接热输入 显微组织 应力腐蚀开裂 慢应变速率拉伸 

分 类 号：TG172.9[金属学及工艺—金属表面处理]