摘要
文章介绍了八钢公司进行X70管线研发的生产工艺路线,采用了三种成分设计(中C-Nb-V-Cr、低C-Nb-V-Cr-Mo和低C-Nb-Ni-Cu-Cr),热轧采用低温轧制和低温卷曲并精确控制出钢温度、粗轧反馈温度和中间坯厚度。三种成分的强度、韧性等指标有如下差异:无论何种成分设计均能得到合格的强度指标和CVN指标,明显差异在于中C-Nb-V-Cr成分DWTT指标在0℃条件下SA%比例不足50%,低C-Nb-V-Cr-Mo和低C-Nb-Ni-Cu-Cr在-30℃条件下SA%仍表现较好的指标,组织进行分析认为:中C-Nb-V-Cr-Mo成分设计中出现严重的平行的偏析带和粗大的板条贝氏体是造成该方案韧性指标不合格的主要原因,低C成分设计可得到针状铁素体+少量贝氏体,M-A组元呈弥散分布,并有效降低铸坯带状偏析,可使材料获得良好的强韧性。
This paper introduced X70 pipeline steel production process,three kinds of composition design were used（mediumC-Nb-V-Cr,lowC-Nb-V-Cr-Mo or lowC-Nb-Ni-Cu-Cr）.Lowtemperature rolling and coiling are adopted in hot rolled process and tapping temperature,temperature fed back from rough rolling and CVN index are controlled accurately.Difference of strength and toughness among three compositions exist as follows： no matter what compositions design can obtain eligible strength and CVN index.Distinguished difference lies in that SA% is less than 50% at zero temperature for DWTT index of medium C-Nb-V-Cr composition,and SA% at-30 degrees for lowC-Nb-V-Cr-Mo and lowC-Nb-Ni-Cu-Cr remains excellent index.Results of structure analysis showthat serious parallel segregation band and thick batten-like Bainite are the main factors resulted in disqualified toughness for the composition project,the composition design with lowcarbon get excellent strength and toughness because it can obtain acicular ferrite and a little Bainite with M-A islands being distributed with dispersion,and slight segregation because of lowcarbon content.
出处
《新疆钢铁》
2010年第3期1-4,共4页
Xinjiang Iron and Steel
关键词
管线钢
设计
强度
韧性
组织
pipeline steel
design
strength
toughness
structure
