S355热轧H型钢SAW焊接接头微观组织与低温冲击性能研究  

Microstructure and low-temperature impact properties of saw welded joint of S355 hot-rolled H-beam steel

作　　者：方革新 Fang Gexin(Personnel Examination Bureau Of Maanshan(Occupational Skill Testing Authority Of Maanshan),Maanshan 243011,Anhui,China)

机构地区：[1]马鞍山市人事考试院(市职业技能鉴定指导中心),安徽马鞍山243011

出　　处：《金属加工（热加工）》2024年第10期52-56,共5页MW Metal Forming

摘　　要：采用埋弧焊(SAW)焊接S355热轧H型钢,利用光学显微镜和扫描电镜观察焊接接头微观组织,按照欧洲标准对焊接接头进行显微硬度测试和低温冲击性能试验,利用SEM观察断口形貌进行分析。结果表明:焊缝区组织主要由针状铁素体+珠光体构成;热影响区由粗晶区、细晶区和不完全重结晶区构成,粗晶区组织主要由粗大的铁素体+珠光体+少量的块状铁素体+粒状贝氏体构成;细晶区组织由细小均匀的铁素体和珠光体构成;不完全重结晶区组织由细小的铁素体、珠光体及原始母材带状组织构成。焊接接头各区域维氏硬度分布均匀,均<185HV10。焊接接头-40℃冲击吸收能量在熔合线位置最高,在其他位置均有一定的降低,冲击性能均满足使用要求。S355 hot-rolled H-beam was welded by SAW.The microstructure of the welded joint was observed by optical microscope and scanning electron microscope.The microhardness and low temperature impact property of the welded joint were tested according to requirements of European standards,and the fracture morphology was observed by scanning electron microscope.The results show that the microstructure of weld zone is mainly composed of acicular ferrite and pearlite,the microstructure of heat-affected zone(HAZ)is composed of coarsegrained zone,fine-grained zone and incomplete recrystallization zone,the coarse-grained zone is mainly composed of coarse ferrite and pearlite,and a small amount of massive ferrite and granular bainite,the fine-grained zone is composed of fine ferrite and perlite.The microstructure of partially recrystallized zone is composed of fine ferrite,pearlite and banded structure of original base metal.The Vickers hardness of the welded joints is less than 185HV10 which uniform distributed in all areas of welded joints,and the impact toughness at-40℃of the welded joints meets the requirements and it is highest at the fusion line position and decreases at all other positions.

关 键 词：S355 SAW 显微组织 低温冲击性能 

分 类 号：TG407[金属学及工艺—焊接]