50 mm厚EH36船板钢冲击性能不合原因分析及改进措施  

Cause analysis and improvement measures of unqualified impact performance of 50 mm thickness EH36 ship plate steel

作　　者：郝鑫 安海玉 郑文超 李行 HAO Xin;AN Haiyu;ZHENG Wenchao;LI Hang(Tangshan Medium and Heavy Plate Co.,Ltd.,Tangshan 063000,China)

机构地区：[1]唐山中厚板材有限公司,河北唐山063000

出　　处：《轧钢》2024年第6期112-115,共4页Steel Rolling

摘　　要：针对实际生产中50 mm厚EH36级船板钢低温冲击性能不合问题,分析了其原因并提出了改进措施。结果表明:50 mm厚EH36级船板钢冲击不合试样金相组织中存在MnS和CaO-Al_(2)O_(3)系夹杂物,同时其1/4厚度处组织为粗大的铁素体和珠光体,是导致其低温冲击韧性不合的主要原因。通过优化炉外精炼工艺提高钢水洁净度,优化控轧控冷工艺细化铁素体晶粒,50 mm厚EH36船板钢中未发现MnS夹杂物,CaO-Al_(2)O_(3)系夹杂物级别控制在1.0级以下,钢板1/4厚度处金相组织主要为晶粒细小的铁素体组织,-40℃冲击功平均值提高到200 J以上,有效解决了50 mm厚EH36船板钢低温冲击不合问题,显著提高了其低温冲击韧性。Aiming at the problem of unqualified low-temperature impact performance of 50 mm thickness EH36 grade ship plate in actual production,the reasons were analyzed and the improvement measures were applied.The results show that the presence of MnS and CaO-Al_(2)O_(3) type inclusions in the microstructure of the 50 mm thickness EH36 ship plate sample,as well as coarse ferrite and pearlite at 1/4 thickness,are the main reasons for its poor low-temperature impact toughness.The cleanliness of molten steel was improved by optimizing the secondary refining process,the ferrite grains were refined by optimizing the controlled rolling and controlled cooling process,no MnS inclusions were found in 50 mm thickness EH36 ship plate,and the inclusion level of CaO-Al_(2)O_(3) type was controlled below 1.0 grade.The microstructure were mainly fine-grained ferrite at 1/4 thickness of the plate.The average impact toughness level under-40℃was increased to more than 200 J.The unqualified low temperature impact performance problem of 50 mm thickness EH36 ship plate has been effectively solved,and its low temperature impact toughness has been significantly improved.

关 键 词：EH36船板钢 低温冲击韧性 夹杂物 控轧控冷 工艺优化 

分 类 号：TG1[金属学及工艺—金属学]