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.