试样减薄对厚壁管线管DWTT性能影响研究

Influence of Specimen Thickness Reducing on the DWTT Properties of the Heavy Wall Thickness Linepipe

采用摆锤式试验机和落锤试验机分别测试了厚壁钢管在20℃、0℃、-10℃、-30℃、-50℃以及-70℃等温度下DWTT性能,试样包括外表面减薄、从钢管内表面减薄、双面减薄以及全壁厚等4类试样。通过测量剪切面积,拟合出各类试样相应韧脆转变曲线,并推测出各类试样韧脆转变温度FATT50%。结果显示,同样试验条件下,减薄试样测试结果优于全壁厚试样结果,而且落锤试验机测试结果优于摆锤试验机结果。

The series DWTT properties of the heavy wall thickness linepipe were tested by both traditional drop weight tear test machine and the 50000 J pendulum impact testing machine at the temperature of 20℃,0℃,- 10℃,- 30℃,- 50℃ and- 70℃ respectively. The series specimens were designed as the reduced specimen from the outside surface,reduced specimen from the inside surface,reduced specimen from the both side and the whole scale thickness specimen. The shear area of each specimen was measured and calculated,and the ductile-brittle transition curve of each sorts of specimen was fitted,so that the ductile-brittle transition temperature（ FATT50%） was estimated. The results showed that the reduced specimens were better than the whole scale thickness specimen,so did the drop weight tear test.