加热速率对双相钢微观组织和烘烤硬化性能的影响  

Effect of heating rates on microstructure and bake hardening behavior of DP steel

作　　者：孙红云[1] 李俊[2] 孟庆格[2] 徐德超[3] 胡文彬[1] 

机构地区：[1]上海交通大学材料科学与工程学院,上海200240 [2]宝钢集团中央研究院,上海201900 [3]东北大学材料与冶金学院,辽宁沈阳110004

出　　处：《锻压技术》2014年第4期115-121,共7页Forging & Stamping Technology

基　　金：十二五国家科技支撑计划项目(2011BAE13B01;2011BAE13B03)

摘　　要：应用自主开发的快速热处理实验设备对双相钢（0．1C-0．2Si-1．3Mn）进行了不同加热速率（5～350℃·s^-1）的连续退火模拟实验，并利用扫描电镜、透射电镜和内耗仪等设备对微观组织和烘烤硬化性能（BHBehavior）及相关机理进行了分析讨论。实验发现，随着加热速率的提高晶粒尺寸可明显细化（8．5～3．9μm），马氏体含量随加热速率的升高有增大的趋势，BH值随着加热速率的提高从62MPa升高到82MPa。分析可知，快速加热条件下BH值的升高的主要因素可能为：高加热速率所导致的较高的位错密度；较高马氏体含量在烘烤阶段所析出η-碳化物对位错的钉扎。The continuous annealing simulation of dual-phase （DP） steel （0. 1C -0. 2Si - 1.3Mn） under different heating rates （5 - 350 ℃·s^-1 ） was conducted using self-developed rapid heat treatment equipment. The effect of heating rate on microstructure and bake hardening behavior was investigated using SEM, TEM and internal friction instrument. It is found that the grain size is minimized, the volume fraction of martensite has increasing tendency with the heating rate increasing and the BH Value is improved from 62 to 82 MPa. Based on the analysis, the main factors for BH value improvement under faster heating state are higher dislocation density caused by higher heating rate and the pinning effect of epsilon carbide precipitated during baking stage when the rtensite volume is higher, and higher heat- ing rate had a strong effect on BH value.

关 键 词：加热速率 双相钢 烘烤硬化性能 内耗 

分 类 号：TG142.1[一般工业技术—材料科学与工程]