Ti型550NH高强度耐候钢板带的力学性能与成形性研究  

Study on Mechanical Properties and Formability of Ti Type 550NH High Strength Weather Resistant Steel Strip

作　　者：李宗强 张盛华 LI Zongqiang;ZHANG Shenghua(Technical Center,Guangxi Liuzhou Iron and Steel Group Company Limited,Liuzhou 545002,China;School of Resources,Environment and Materials,Guangxi University,Nanning 530004,China)

机构地区：[1]广西柳州钢铁集团有限公司技术中心,广西柳州545002 [2]广西大学资源环境与材料学院,广西南宁530004

出　　处：《热加工工艺》2022年第23期96-101,共6页Hot Working Technology

基　　金：广西柳州市科技计划项目(2021AAD0101)。

摘　　要：为了全面研究550NH型耐候钢带的力学性能和成形性,通过改变试验钢中Ti元素的含量,设计了三种耐候钢。结合冶炼工艺、轧制工艺进行了钢的试制,并用光学显微镜、扫描电镜分析了钢轧后的显微组织和冲击断口,进行了拉伸和冲击试验。结果表明,在高卷取温度下,试验钢的组织均为铁素体基体+部分珠光体,延长加热的保温时间,适当降低终轧温度,可有效减轻甚至消除珠光体带状组织;在力学性能方面,Ti元素在热轧过程中起到了细晶强化与析出强化的双重作用,但过多的Ti元素含量会降低材料的韧塑性;在成形性方面,不含带状组织的试验钢由于具有均匀分布的F+P组织,其冷弯性能较好;含带状组织的试验钢则出现了明显的冷弯裂纹,材料的塑性变形能力下降。In order to comprehensively study the mechanical properties and formability of Ti type 550NH weather resistant steel strip, three kinds of weather resistant steel were designed by changing the content of Ti element in the test steels.Combined with the smelting process and rolling process, the trial production of steel was carried out. The microstructure and impact fracture of the steel after rolling were analyzed by optical microscope and scanning electron microscope, and tensile and impact tests were carried out. The results show that at high coiling temperature, the structure of the test steel is ferrite matrix + part of pearlite. Extending the insulation time for the heating and appropriately reducing the final rolling temperature can effectively reduce or even eliminate the pearlite band structure. In terms of mechanical properties, Ti element plays a dual role of grain refinement strengthening and precipitation strengthening during hot rolling, but too much Ti element content will reduce the toughness and plasticity of the material. In terms of formability, the test steel without band structure has better cold bending performance because of the uniform distribution of F+P structure;the test steel with banded structure has obvious cold bending cracks, and the plastic deformation ability of the material decreases.

关 键 词：550NH耐候钢 Ti元素 力学性能 成形性 珠光体带状组织 

分 类 号：TG335.11[金属学及工艺—金属压力加工]