摘要
以220 MPa级超低碳烘烤硬化钢为研究对象,对比分析Nb单加体系(H220BD-1)与Nb+Ti双加体系(H220BD-2)的试验钢,通过固溶碳计算及内耗法测定,探究2种成分体系下固溶碳对时效行为的影响,并结合微观组织晶粒尺寸分析,阐明晶粒尺寸与烘烤硬化(BH)值、耐时效性能的关联机制。结果表明:Ti的添加显著降低固溶碳含量,抑制时效过程中碳原子的动态偏聚,同时双加体系细化晶粒,通过Hall-Petch效应提升强度并改善耐时效稳定性。为优化烘烤硬化钢成分设计及解决时效问题提供了理论依据。
Taking 220 MPa grade ultra-low carbon bake-hardening steels as the research object,this paper compares and aralyzes test steel with Nb single-addition(H220BD-1)and Nb+Ti dual-addition(H220BD-2)systems.Through solid solution carbon calculations and internal friction method determination,the paper explores the influence of solid solution carbon on aging behavior under different composition systems,and combines with microstructure griain size characterization to elucidate the correlation mechanism between grain dimensions and Bake-Hardening(BH)value with aging resistance.Results demonstrate that Ti addition significantly reduces solid solution carbon content,effectively suppressing dynamic carbon segregation during aging.The dual-addition system achieves grain refinement,enhancing strength via Hall-Petch effect while improving aging stability.
作者
肖景江
郭强
吴庆美
卜凡征
郑连辉
Xiao Jingjiang;Guo Qiang;Wu Qingmei;Bu Fanzheng;Zheng Lianhui(TKAS Auto Steel Co.,Ltd.,Dalian 116600)
出处
《汽车工艺与材料》
2025年第8期56-60,共5页
Automobile Technology & Material
关键词
烘烤硬化钢
固溶碳
耐时效性
晶粒细化
Bake-hardening steels
Solid solution carbon
Aging resistance
Grain refinement
