大口径厚壁管压扁试验和弯曲试验严格程度的比较

对电站锅炉用大口径厚壁管进行了压扁和弯曲对比试验,分析了试样受拉面塑性变形的差异,比较了两种试验的试样形状和合格判据要求的差异,讨论了锅炉常用ASME SA-335MP91/92钢管的压扁试验和弯曲试验在工程应用中的相关问题。结果表明:钢管弯曲试验的塑性变形明显大于压扁试验,对材料塑性要求更为严格;建议今后国内制定或修订相关标准时,进一步放宽大口径厚壁管弯曲试验替代压扁试验的限制。

Comparison of Severity of Flattening Test and Bending Test for Large Diameter and Heavy Wall pipes

Comparative investigation of flattening test and bending test for large diameter and heavy wall pipes used for boiler was performed, the tension plastic deformation differences of these two kinds of tests were analyzed, and the required test samples and acceptance criterion of these two kinds of tests were also compared. Meanwhile, the related issues of practical application for these two kinds of tests on P91/P92 steel pipes majorly used for boiler were discussed. The results show that the tension plastic deformation of bending test was much more than that of flattening test, and flattening test was suggested to be more substituted by bending test for large diameter and heavy wall pipe while drafting or modification of related standards.