电磁搅拌对管线钢板坯质量和钢板性能的影响

Effect of S-EMS on slab quality and mechanical properties of linepipe plate

详细对比了使用电磁搅拌(S-EMS)和未使用S-EMS的管线钢板坯质量和轧制后钢板性能,研究S-EMS对管线钢板坯质量和钢板性能的影响。对比结果显示:使用S-EMS后,板坯的中心偏析和疏松显著改善,板坯中心等轴晶率由12%提高到26%。管线钢的冲击性能(-20℃)和落锤性能(-15℃)得到了显著改善,钢板的中心组织以均匀细小的针状铁素体为主,基本消除了中心条带状偏析带、粗大魏氏体和颗粒状贝氏体组织。轧制后钢板的常规冲击KV2≥350 J所占比例为100%;落锤剪切面积比SA样本合格率提高了2.65%,达到了100%。

The slab internal quality and the mechanical properties of linepipe plate with and without in-strand roller type electromagnetic stirring （S-EMS） were studied. The results showed that the centerline segregation and center porosity of slab macroscopic structure were improved with the proper use of S-EMS. The central equiax crystal ratio was increased from 12 % to 26 %. The impact properties （ - 20℃） and the drop weight tear（ - 15℃）were improved remarkably. The detrimental segregation bandings, coarse Widmannstatten and granular Bainite structures were greatly reduced. The ratio for KV2≥350 J of rolled plate samples got to 100%, the qualified rate for the shear fracture area of drop weight tear test was increased 2. 65 %, and got to 100 %.