【作者】 刘宏亮； 黄健； 郑中； 赵迪； 刘清友； 姜茂发；

【Author】 Liu Hongliang;Huang Jian;Zheng Zhong;Zhao Di;Liu Qingyou;Jiang Mao-fa;Benxi Steel Group Corporation;China Iron & Steel Research Institute Group;School of Materials and Metallurgy, Northeastern University;

【机构】 本钢集团有限公司； 中国钢研科技有限公司； 东北大学材料与冶金学院；

【摘要】 通常认为增加精轧应变可以有效细化管线钢组织,从而提高管线钢的强度和韧性,然而,随着产品厚度的增加,该调整方法受设备的限制,成为生产技术瓶颈。本研究采用Gleeble-2000热模拟试验机、金相分析、扫描电镜技术等系统研究了轧制工艺对管线钢组织和性能的影响。研究结果表明:厚规格产品韧性不符合标准归因于边部和心部冷却梯度增加,边部以粒状贝氏体组织为主,而心部存在多边形铁素体,这种组织梯度最终引起韧性的恶化。热模拟分析结果表明,通过减小精轧应变增加铁素体孕育时间,可以有效避免这一问题。依据研究结果,结合理论分析制定了减小中间坯厚度的生产工艺,并进行了X70和X80工业试验,管线钢强度和韧性均有明显增加,韧性不稳定问题得到解决,最终形成了稳定、批量生产厚规格管线钢产品的新工艺。更多还原

【Abstract】 It is widely acknowledged that increasing fine rolling strain can effectively refine the microstructure, and contributing greatly to improve the strength and toughness of pipeline steel. However, with increasing the thickness of the product, this method restricted by the capacity of equipment, and become bottlenecks in the production. In this paper Gleeble-2000 thermal simulation test machine, metallographic analysis, SEM technology, et al. has been used to study the effect of rolling process on the microstructure and properties in pipeline steels. The results show that: because of the increased gradient of cooling rate between edge and core in thickness specification product, the microstructure of edge is mainly characteristic of granular bainite(GB), but polygonal ferrite(PF) increased in core. This property resulted in toughness deterioration. Thermal simulation analysis results show that, the PF transformation incubation time can be increased by reducing the rolling strain, which is useful to avoid the problem. According to the results and theoretical analysis, the production process of reducing the thickness of intermediate billet is formulated. And industrial experiments were carried out with X70 and X80 pipeline steels. Surprisingly, the strength and toughness were significantly increased, and the problem of toughness instability was solved as expected. At last, a new technology for producing thickness pipeline steel is developed.更多还原