冷轧工艺对301L不锈钢组织及性能的影响

发布时间：2018-12-21 15:49

【摘要】：近年来,轨道交通快速发展使轨道车辆车体材料的研究成为焦点。301L不锈钢因为具有较高强度、耐腐蚀性好等优点,被选作轨道车辆车体材料使用,并通过形变强化,在保证强度的情况下,可降低材料厚度达到轻量化和节能减排的目的。由于301L不锈钢板材在冷轧生产过程中的轧制参数不易控制,生产难度较高等问题,本文为此主要研究了冷轧变形量对301L不锈钢板材组织与性能的影响规律,为实际生产提供一定技术参考。试验制备了标准成分的301L不锈钢,将其进行锻造、热轧和冷轧处理,开展了变形量对冷轧试样显微组织和拉伸性能的研究。研究表明,在冷轧过程中,随变形量增大,位错增殖、在晶界附近塞积,造成晶粒变形;晶粒中出现交叉滑移带,为马氏体形核提供场所;大变形量时,晶粒出现纳米化现象,衍射斑点呈环状;变形时晶粒发生偏转,γ(220)面逐渐与轧向平行;材料中产生加工硬化和晶粒细化,并发生马氏体相变,导致材料强度、硬度提升,塑性、韧性下降;在15%压下率时,抗拉强度达到965MPa,屈服强度达到677MPa,硬度达到335HV,延伸率为49%;在40%压下率时,材料抗拉强度、屈服强度、硬度分别为1317MPa、1274MPa和469HV,延伸率显著下降;随着冷轧过程中压下率的增加,301L不锈钢的形变硬化指数(n值)由0.357%降至0.030%。
[Abstract]:In recent years, the rapid development of rail transit has made the research of rail vehicle body material become the focus. 301L stainless steel has been selected as the material of rail vehicle body because of its high strength and good corrosion resistance, and strengthened by deformation. Under the condition of guaranteed strength, the material thickness can be reduced to achieve the purpose of light weight and energy saving and emission reduction. Because the rolling parameters of 301L stainless steel sheet are not easy to control and the production difficulty is high during the cold rolling process, the effect of cold rolling deformation on the microstructure and properties of 301L stainless steel sheet is studied in this paper. Provide certain technical reference for actual production. The standard 301L stainless steel was prepared by forging, hot rolling and cold rolling. The microstructure and tensile properties of cold rolled stainless steel were studied. The results show that in the cold rolling process, with the increase of deformation amount, dislocation proliferates, and the grain deformation is caused by plugging near grain boundaries, and there are cross slip bands in the grains, which provide a place for martensite nucleation. Nanocrystalline grains appear nanocrystalline in large amount of deformation, diffraction spots appear annular, grain deflections occur during deformation, 纬 (220) plane is gradually parallel to rolling direction. Work hardening, grain refinement and martensite transformation occur in the material, which leads to the increase of strength, hardness, plasticity and toughness of the material. The tensile strength, yield strength, hardness and elongation were 965 MPA, 677 MPA, 335 HVand 49, respectively, and the tensile strength, yield strength and hardness were 1317MPa 1274MPa and 469HVrespectively. The deformation hardening index (n value) of 301L stainless steel decreased from 0.357% to 0.030% with the increase of reduction rate during cold rolling.
【学位授予单位】：西华大学
【学位级别】：硕士
【学位授予年份】：2018
【分类号】：TG337.5

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