单次淬火对大厚度FH790海工钢微观组织和性能的影响  

Effect of single quenching on the microstructure and properties of large thickness marine steel FH790

作　　者：赵喜伟 龙杰 庞辉勇 王九清 ZHAO Xiwei;LONG Jie;PANG Huiyong;WANG Jiuqing(HBIS Group Wusteel Company,Wugang 462500,China)

机构地区：[1]河钢集团舞钢公司,河南舞钢462500

出　　处：《冶金分析》2024年第8期34-40,共7页Metallurgical Analysis

基　　金：国家重点研发计划(2016YFB0300601)。

摘　　要：利用力学检测设备、光学显微镜(OM)、扫描电子显微镜(SEM)和透射电子显微镜(TEM)等先进手段研究分析了大厚度FH790海工钢单次淬火+回火热处理后不同厚度位置的力学性能和微观组织。结果表明:大厚度FH790海工钢仅进行一次淬火+回火热处理后,不同厚度位置的屈服强度和抗拉强度差别不大,都能满足船级社规范要求,但是离钢板表面1/4厚度(T/4)位置冲击功均值为58 J,距离钢板表面1/2厚度(T/2)芯部位置冲击功均值为26 J,很难达到船级社规范的要求,主要原因是大厚度FH790海工钢厚度T/2芯部位置存在大量的回火粒状贝氏体组织,这种微观组织的有效晶粒尺寸相对较大,导致了冲击韧性相对较差。The mechanical properties and microstructure of large thickness marine steel FH790 at different thickness positions after single quenching and tempering heat treatment were studied and analyzed by advanced methods,including mechanical testing equipment,optical microscopy(OM),scanning electron microscopy(SEM),and transmission electron microscopy(TEM).The results showed that the yield strength and tensile strength at different thickness positions of large thickness marine steel FH790 after only single quenching and tempering heat treatment had little difference,which could meet the classification society rules.However,the average impact energy at the 1/4 thickness(T/4)position was 58 J,and the average impact energy at the 1/2 thickness(T/2)core position was 26 J,which could hardly meet the classification society rules.The main reason was that there was a large amount of tempered granular bainite structures in the core of marine steel FH790 with a thickness of T/2.And the effective grain size of this microstructure was relatively large,which resulted in relatively poor impact toughness of the steel plate.

关 键 词：大厚度FH790海工钢 微观组织 冲击韧性 马氏体组织 贝氏体组织 

分 类 号：TF031[冶金工程—冶金物理化学] TG115[金属学及工艺—物理冶金] TG142[金属学及工艺—金属学]