快冷工艺对800MPa级低碳高强贝氏体钢力学性能的影响  

Influence of fast cooling on mechanical property of 800 MPa grade steel with low carbon bainite structure

作　　者：谢保盛 蔡庆伍[1,2] 曹嘉明[2] 宁榛 程磊[1] 

机构地区：[1]北京科技大学钢铁共性技术协同创新中心,北京100083 [2]北京科技大学高效轧制国家工程研究中心,北京100083

出　　处：《材料热处理学报》2015年第10期110-116,共7页Transactions of Materials and Heat Treatment

基　　金：国家自然科学基金(51274036)

摘　　要：设计了一种低碳贝氏体型高强度工程机械用钢,并采用快速冷却工艺进行厚度12 mm的Q800D钢的轧制试验,研究了冷却速率对钢板组织、强度和韧性的影响。结果表明,随着钢板冷却速率的增加,小角度晶界和大角度晶界密度均有较大提高,钢板强度和韧性有明显改善。当钢板冷却速度为80℃/s时,钢板综合性能达到国标Q800D级别的要求。另外,在考虑到晶界和M/A组元对韧性影响的基础上计算了不同冷却速度钢板的韧性参数,韧性参数随冷速的变化趋势与-20℃冲击功随冷速的变化趋势一致,两者有良好的相关性。A kind of low carbon bainitic steel for construction machinery were designed,and the effects of cooling rate on microstructure,strength and toughness of Q800 D steel with thickness of 12 mm were studied. The results show that,with the increase of cooling rate in the steel,the density of the low angle grain boundaries and high angle grain boundaries increases,and the strength and toughness of the steel can improve. When cooling rate is 80 ℃ / s,the steel conforms to national standard for Q800 D steel. Besides,considering the influence of grain boundary and M / A islands on the toughness,toughness factors under different cooling rates are calculated and found to be consistent with impact energy,which indicates good correlation between toughness factors and impact energy.

关 键 词：Q800D 冷却速率 取向差角 有效晶粒尺寸 力学性能 

分 类 号：TG142.1[一般工业技术—材料科学与工程]