吉林建龙提高管线用L360M钢卷DWTT断口剪切面积的研究

Study on improving DWTT fracture shear area of l360m coil for pipeline in Jilin Jianlong

为了提高管线用L360M钢卷落锤撕裂试验(以下简称DWTT)断口剪切面积,深入研究了化学成分、显微组织和力学性能对DWTT断口剪切面积的影响,研究发现较高的钢水纯净度、合理的成分设计、较高的冷却速率及均匀细化的显微组织是提高DWTT断口剪切面积的关键,微合金强化对形变奥氏体再结晶起到抑制作用,钙处理提高钢水洁净度,连铸机动态轻压下改善铸坯中心偏析、中心疏松、中间裂纹,提高板坯的组织均匀性,提高冷却速率,从而提高强度、韧性、成形性,结果表明,通过上述生产工艺的研究开发,使管线用L360M钢卷DWTT断口剪切面积百分比均值达到99.2%,优于标准要求≥85%。。

In order to improve the fracture shear area of L360M steel coil drop weight tear test(hereinafter referred to as DWTT)for pipeline,the effects of chemical composition,microstructure and mechanical properties on the fracture shear area of DWTT are deeply studied.It is found that higher purity of molten steel,reasonable composition design,higher cooling rate and uniformly refined microstructure are the key to improve the fracture shear area of DWTT,Microalloy strengthening can inhibit the recrystallization of deformed austenite,calcium treatment can improve the cleanliness of molten steel,dynamic soft reduction of continuous caster can improve the central segregation,central porosity and intermediate crack of slab,improve the microstructure uniformity of slab and improve the cooling rate,so as to improve the strength,toughness and formability.The results show that through the research and development of the above production process,Make the average percentage of fracture shear area of DWTT of L360M steel coil for pipeline reach 99.2%,which is better than the standard requirement of≥85%.