Evaluation of centreline segregation m continuously cast line pipe steels
Centreline segregation occurs as a positive concentration of alloying elements like C,Mn and P in the last to solidify mid thickness region of continuously cast slab.Depending upon its degree,it may be harmful to the weldability and integrity of line pipe.In the USA control of segregation is required to Mannesmann 2 or better based on a Mannesmann scale of ratings 1 to 5 for high design factor pipelines,and PRCI recommend 1 or better for when centre slit strip is used,or for sour service.While methods for the control of segregation like caster design and maintenance,super heat,and casting speed are well known,there is no international consensus on evaluation methods for assessment,and different methods,are used by different suppliers.The most pressing problem is the coarse graduation of the Mannesmann scale which not only lends itself to disagreements on rankings with customers but also an inability by the steelmaker to critically evaluate processing parameters for improvement in continuous casting production processes.This paper reports an evaluation of current techniques for assessment and quantification of centre line segregation.Potential methods have been identified for industrial trials,including etching techniques,evaluation methods and quantification with better sensitivity and reproducibility.
centreline segregation line pipe steel continuously cast
L Su XU G GUI G H Li C Lu I Simpson F Barbaro L Fletcher ZHENG L BAI M SHEN J
University of Wollongong,Australia Baoshan Iron & Steel Co.,Ltd.,Shanghai 201900,China Energy Pipelines CRC,Australia
国内会议
上海
英文
1-8
2013-06-01（万方平台首次上网日期，不代表论文的发表时间）