50Mn热轧带钢的研制与生产实践

Development and Production Practice of Hot Rolled 50Mn Strip Steel

根据产品的用途和用户专业化的需求,结合国家标准,系统分析了中碳钢种中50Mn热轧带钢技术要求,重点研究了该钢种的化学成分设计、加热工艺、轧制工艺和层流冷却工艺。在新天钢联合特钢650热连轧带钢生产线上,采用堆冷坯加热→全连续轧制→层流冷却→卧式卷取→堆冷工艺,进行了50Mn热轧带钢大生产实践。生产实践结果表明:50Mn-1和50Mn-2抗拉强度分别为747~800 MPa和800~864 MPa,总脱碳层深度分别为19.10μm和24.15μm,产品力学性能和总脱碳层深度指标符合国家标准和技术协议要求,金相组织为铁素体+珠光体,成品尺寸、板形及表面质量良好,满足用户后续加工的要求。

According to the purpose of the product and the needs of users specialization,combined with the national standards,this paper systematically analyzed the technical requirements of hot rolled 50Mn strip steel,which belongs to the medium carbon steel grade,and focused on the chemical composition design,reheating process,rolling process and laminar cooling process for the steel grade.In the 650 hot strip rolling line at Tianjin New Tiangang United Special Steel Co.,Ltd.,the process of slab-stacking cooling→slab reheating→full continuous rolling→laminar cooling→horizontal coiling→stack cooling was adopted.The production practice of the strip has been carried out.The production practice results show that the tensile strength of 50Mn-1 and 50Mn-2 are 747~800 MPa and 800~864 MPa respectively,and the total decarburization depth of 50Mn-1 and 50Mn-2 is 19.10μm and 24.15μm respectively.The mechanical properties and total decarburization depth index of the product meet the requirements of national standards and technical agreements.The metallographic structure is ferrite+pearlite.The size,shape and surface quality of the finished product are good,meeting the user s requirements for subsequent processing.