18CrNiMo7-6齿轮钢一次带状组织特征  

As-cast banded structure characteristics of 18CrNiMo7-6 gear steel

作　　者：曹杰瑞 徐文博 闫来平 郭长庆[1] Cao Jierui;Xu Wenbo;Yan Laiping;Guo Changqing(School of Material Science and Engineering, Jiangsu University, Zhenjiang Jiangsu 212013,China;Jinkun Forging Co.,Ltd.,Changzhou Jiangsu 213300,China)

机构地区：[1]江苏大学材料科学与工程学院,江苏镇江212013 [2]江苏溧阳金昆锻压有限公司,江苏常州213300

出　　处：《金属热处理》2019年第3期16-21,共6页Heat Treatment of Metals

摘　　要：风力发电用齿轮钢18CrNiMo7-6经过电弧炉初炼、LF炉和VD炉精炼后浇入到钢锭模中,随后采用光学显微镜(OM)、扫描电镜(SEM)和能谱(EDS)对试验用钢中的一次带状组织的特征进行了观察和分析。结果表明:18CrNiMo7-6齿轮钢铸态组织中存在着严重的一次带状组织,该带状组织宽大,平均宽度达225μm,长度达800μm。其中,珠光体带约占58. 6%。根据GB/T 13299—1991评定带状组织的等级为3～4级,根据美国ASTME1268-2001评定带状组织级别为3. 897。EDS线扫描与面扫描发现C、Cr元素在枝晶间偏析严重,是导致一次带状组织形成的主要原因。The 18CrNiMo7-6 wind-power gear steel was produced with the processes of electric arc furnace melting → LF refining → VD refining→casting in ingot mould. Then,the as-cast banded microstructural features of the tested steel were investigated by means of optical microscope,scanning electron microscope and energy dispersion spectrum. The results show that there are heavy banded microstructure in the as-cast tested steel,with its average width being 225 μm,average length 800 μm,and in which the area proportion of pearlite band is about 58. 6%. The banded structure is grade 3-4 according to GB/T 13299-1991 and grade 3. 897 according to ASTME 1268-2001,respectively.It is found by EDS analysis that serious segregation of C and Cr in dendritic segregation is the main cause of the as-cast banded structure in 18 CrNiMo7-6 gear steel.

关 键 词：一次带状组织 18CrNiMo7-6齿轮钢 枝晶偏析 

分 类 号：TG142.1[一般工业技术—材料科学与工程]