石油套管用钢带状组织研究

采用硫印、热酸侵蚀、原位分析和SEM扫描电镜及能谱分析等方法,分析J55钢级石油套管铸坯中心元素的偏析,研究加热温度、终轧温度、未再结晶区变形率、终轧后冷速及卷取温度等因素对消除或者减轻带钢中带状组织影响规律。结果表明:Mn元素偏析是引起热轧带钢带状组织的直接原因,采取提高加热温度、终轧温度、未再结晶区大变形率、终轧后冷速及降低卷取温度等措施,可以减轻或者消除由于铸坯中心偏析引起的带状组织。

Research on Banded Microstructure of Steel for Oil Casing Pipe

Center segregation in strand for J55 oil casing pipe is analyzed and the influences of heating temperature,finish rolling temperature,deformation rate in noncrystallization area,cooling rate after finish rolling and coiling temperature etc.on the reduction or elimination of banded microstructure are researched by means of sulfur print,hot acid erosion,OPA,SEM and EDS.The result shows that it is the segregation of Mn that directly leads to the formation of banded microstructure in hot rolled strip,and the problem can be reduced or eliminated by increasing finish rolling temperature,deformation rate in noncrystallization area,cooling rate after finish rolling and coiling temperature and lowering coiling temperature,etc.