烘烤时间对大晶粒低碳钢烘烤硬化性能的影响

第40卷第6期上海金属 Vol.40,No.6

2018年11月 SHANGHAI METALS November ,201845 基金项目:国家自然科学基金(No.51274121)

作者简介:金晓龙,男,主要从事烘烤硬化钢组织与性能的研究,E-mail:ag jinxiaolong@https://www.360docs.net/doc/764988777.html, 烘烤时间对大晶粒低碳钢烘烤硬化性能的影响

金晓龙1 王旭1 刘仁东1 李维娟2

(1.鞍钢集团钢铁研究院,辽宁鞍山 114009;2.辽宁科技大学材料与冶金学院,辽宁鞍山 114051) ?摘要? 测试了大晶粒低碳钢在170?烘烤不同时间的烘烤硬化(BH )值三通过内耗试验获得了相应烘烤工艺的内耗曲线,研究了烘烤时间对大晶粒低碳钢烘烤硬化性能的影响机制三结果表明,当预变形量为5%,烘烤温度为170?时,不同烘烤时间的大晶粒低碳钢的BH 值均为负值;BH 值和SKK 峰随着烘烤时间的延长先增加后不变,BH 值随着SKK 峰的变化而变化,即BH 值主要受Cottrell 气团强化作用的影响三烘烤1000min 的钢的BH 值达到最大,继续延长烘烤时间,BH 值变化不大;当烘烤时间为20min 时,SKK 峰值最大;当烘烤时间超过

1000min 时,SKK 峰高变化不大三?关键词? 低碳钢烘烤硬化内耗 Cottrell 气团预变形

Effect of Baking Time on Bake-hardening Behavior of Low-carbon Coarse-grained Steel

Jin Xiaolong 1 Wang Xu 1 Liu Rendong 1 Li Weijuan 2(1.Iron &Steel Research Institute of Angang ,Anshan Liaoning 114009,China ;2.School of Materials and

Metallurgy ,University of Science and Technology Liaoning ,Anshan Liaoning 114051,China ) ?Abstract ? Bake hardening (BH )value of low-carbon coarse-grained steel after been baking at 170?for different times was measured ,and the internal friction curves corresponding to baking processes were obtained by internal friction experiment.The effect of baking time on bake-hardening behavior of the low-carbon coarse-grained steel was studied.The results showed that when the pre-deformation amount was 5%and the baking temperature was 170?,the BH values of low-carbon coarse-grained steel baked for different times were negative ,the BH value and SKK peak increased first and then remained steady with the extension of baking time ,the BH value varied with the change in SKK peak ,that is ,the BH values was mainly affected by the Cottrell air mass.When the baking time was 1000min ,the BH value reached the maximum ,then less changed as baking time became more long.When the baking time was 20min ,SKK peak reached the maximum ,then less changed as the baking time was above 1000min.

?Key Words ? low carbon steel ,bake-hardening ,internal friction ,Cottrell air mass ,pre-

deformation 汽车用钢的烘烤硬化现象在提高其抗凹陷性能的同时还可以减轻车身质量,在安全性能和节能减排标准不断提高的今天,烘烤硬化钢(BH 钢)得到了广泛的关注,BH 钢成为近几年来汽车

用钢重点研究的对象之一[1-3],其烘烤硬化机制的研究越来越受到重视[4-7]三烘烤硬化的实质是间隙原子和冲压成型过程中形成的位错交互作用

的结果三烘烤时间和晶粒尺寸对烘烤硬化性能有万方数据