高钢级大壁厚管线钢管DWTT影响因素探讨

Discussion on the Influence Factors of DWTT for High Grade and Heavy Wall Thickness Line Pipe

介绍了国内管线钢管生产中落锤撕裂试验(DWTT)常用的标准。对于大壁厚管线钢管的DWTT,可采用全壁厚试样和规定尺寸的减薄试样来进行。从韧脆转变温度、断口剪切面积评判方法和减薄试样加工方法几个方面探讨了高钢级大壁厚管线钢DWTT的影响因素。提出了建议:采用减薄试样DWTT时,应避开材料的韧脆转变温度进行试验;采用单面减薄和双面减薄试样DWTT时,应在标准中明确试样的加工方法;另外,应对不同钢级减薄试样降低相同温度的试验结果进行相应的系数修正。

This article introduced some domestic standards commonly used in drop weight tear test（DWTT） in line pipe production.It can adopt full-wall thickness specimens and the specimens with reduced thickness to carry out DWTT for thick wall line pipes.It discussed the influence factors of DWTT for high grade and heavy wall thickness line pipes from several aspects,such as ductile-brittle transition temperature,method for evaluating percent fracture shear area and machining methods for thinning specimens.Finally,it proposed that when adopting thinning specimen to carry out DWTT,it should avoid the test of ductile-brittle transition temperature of material,and specify the method of machining specimen in standard while adopting one side and two sides reduce wall thickness specimens;In addition,it should carry through corresponding coefficient amendment for tests results of thinning specimens with different grades,under reducing the same temperature.