20MnSiVⅢ级钢筋焊缝和热影响区拉伸脆性断裂的分析  

An Analysis on Tensile Brittle Fracture of Welding Seam and Heat Affected Area of Steel 20MnSiV Ⅲ Grade Reinforced Bar

作　　者：秦斌[1] 盛光敏[1] 龚士弘[1] 

机构地区：[1]重庆大学材料科学与工程学院,重庆400044

出　　处：《特殊钢》2003年第6期59-61,共3页Special Steel

摘　　要：分析了Φ32mm 2 0MnSiVⅢ级钢筋搭接焊试样拉力试验断口—焊缝和热影响区脆性断裂。断口处HV硬度试验和扫描电镜观察表明 ,焊缝和热影响区存在大量魏氏组织和贝氏体 马氏体是拉伸脆性断裂的主要原因 ,夹杂物向晶界偏聚导致沿晶脆性断裂 。The fracture of steel 20MnSiV Φ32 mm III grade reinforced bar bundle welding sample tensile testing - brittle fracture of welding seam and heat affected area has been analyzed. The HV hardness test and SEM observation on fracture show that large amount of Widmannstatten structure and bainite\|martensite in welding seam and heat affected area are main causes of tensile brittle fracture, and mass inclusion segregated at grain boundary lead to intercrystalline brittle fracture. The small heat input multipass welding are available to improve the structure and toughness of heat affected area.

关 键 词：钢筋 搭接焊 拉伸脆性断裂 热影响区 扫描电镜 焊缝 魏氏组织 贝氏体 夹杂物 建筑工程 

分 类 号：TG407[金属学及工艺—焊接]