超级13Cr马氏体不锈钢管韧性低的原因分析和措施

Analysis of Reason for Low Toughness of Super 13Cr Martensitic Stainless Steel Pipe and Relevant Countermeasures

某批次超级13Cr无缝钢管热处理后韧性较低,结合生产工艺,对其显微组织、非金属夹杂物、拉伸性能、冲击功、硬度和化学成分进行检测。分析结果显示:钢管淬火后硬度低,调质后组织不均匀,存在较多与钢管轴线平行的粗大铁素体相,相间分布,割裂了基体组织的连续性,导致了横向冲击功较低;对此批管子和剩余原料提出应对措施,通过增大钢管变形量,改变淬火和回火处理工艺优化了金相组织,提高了产品性能。

Aiming at the event that the post-heat treatment toughness of a certain batch of the super 13Cr seamless steel pipe,based on the manufacturing process,all the tests are conducted to the pipe in terms of microstructure,non-metallic inclusion,tensile property,impact energy and chemical composition.It is revealed via the analysis that after being quenched,the pipe’s hardness is rather low,and due to quenching and tempering treatment,its microstructure is not homogeneous enough,and there exist many coarse ferrite phases as parallel to the axis of the steel pipe,and distributed between the phases,which breaks the continuity of the matrix structure,and leads to the low transverse impact energy.The corresponding countermeasures are put forward and taken for the said batch of pipes and the remaining raw materials,including increasing the deformation amount of the steel pipe,and changing the quenching and the tempering processes so as to optimize the metallographic structure,and thus improve the performance of the product.