摘要
采用光学显微镜和力学性能测试设备研究了不同热处理方式对550 MPa级高强度船板组织和性能的影响。结果表明:随正火温度的升高(低于860℃),组织的变化并不明显,均为铁素体+粒状贝氏体+M/A;继续升高温度,铁素体晶粒尺寸明显粗大,带状组织减轻;钢板的屈服强度、抗拉强度都下降,屈服强度不能满足标准要求。高温热处理再经回火后,组织中的M/A岛几乎完全分解;屈服强度、伸长率及低温冲击韧度明显提高,抗拉强度下降。在高出Ac3点0~40℃进行正火+650℃回火处理,钢板的综合力学性能最佳。
Effects of different heat treatment on microstructure and performance of 550 MPa grade high strength hull plate were studied by means of OM and mechanical testing facilities.The results show that with the increase of normalizing temperature(under 860 ℃),the change of microstructure is not notable,and they are ferrite,granular and M/A island; with the increase of temperature sequentially,the size of ferrite grain grows notably,the banded structure lightens; tensile strength and yield strength of steel plate all decrease,and tensile strength does not satisfyi criteria.By means of drawing temper,M/A islands in microstructure almost completely decompose,yield strength,elongation ratio and low temperature impact toughness increase,but tensile strength of steel plate decreases.With normalizing at range of 0-40 ℃ above Ac3 point and tempering at650 ℃,best mechanical properties are obtained.
出处
《热加工工艺》
CSCD
北大核心
2015年第6期223-225,228,共4页
Hot Working Technology
关键词
船板
热处理
组织
M/A岛
hull plate
heat treatment
microstructure
M/A island