摘要
针对汽车转向轴用E355钢焊管裂纹问题,通过金相组织分析和扫描电镜分析等试验方法对钢管进行了失效分析。分析结果显示,裂纹为沿钢管轴向裂纹,位于钢管外壁母材处,焊缝位置无开裂;焊管基体带状组织严重;原始裂纹处主要以铁氧化物为主,且O含量最高为14.42%,氧化程度较轻。研究表明,焊管基体带状组织严重是导致钢管裂纹的重要原因,建议从控制热轧酸洗板原料连铸板坯偏析缺陷着手,优化冶炼工艺,有效降低焊管裂纹缺陷。
Aiming at the problem of the crack of E355 steel welded pipe,the failure analysis of the steel pipe was carried out by means of the metallographic structure analysis and SEM analysis.The results show that the cracks are along the axial direction of the steel pipe,located in the outer ring of the steel pipe,not in the position of the weld.The original cracks are mainly iron oxides,the highest oxygen content is 14.42%and the oxidation is relatively light.The results show that the serious banded structure of the welded pipe matrix is an important reason for the crack of the steel pipe.It is suggested to optimize the smelting process and effectively reduce the crack defects of the welded pipe by controlling the segregation defects of the continuous casting slab.
作者
张龙超
ZHANG Longchao(Science and Technology Quality Department,Xichang Steel and Vanadium Co.,Ltd.,Xichang 615032,Sichuan,China)
出处
《焊管》
2020年第4期44-47,51,共5页
Welded Pipe and Tube
关键词
E355钢
焊管
裂纹
带状组织
中心偏析
E355 steel
welded pipe
crack
banded structure
central segregation
