Fig. 5 Sampling(among them, 4-5 is the element analysis sample, 4-6 is the metallographic sample, 4-8 is the tensile sample, 4-1, 4-2, 4-3, 4-4 is the impact sample)
2.3.1Tensile test
Sampling shall be carried out according to Fig.5 and GB /T228.1-2010metal material tensile test Part 1: room temperature test method , and the test shall be carried out with Metz microcomputer servo universal testing machine. Test results: the yield strength is 860MPa (755-890MPa as required by the standard), the tensile strength is 899 MPa (890-1030MPa as required by the standard), the elongation after fracture is 18.9% (16% as required by the standard), and the area shrinkage is 62.7% (55% as required by the standard).The tensile properties of these two samples are comparable with the specification requirements according to GB/T 8732. Tensile properties of the cracked blade are also in accordance with the design standard。
2.3.2 Impact test
According to GB / T229-2007Metallic materials Charpy pendulum impact test method , 4-1, 4-2, 4-3, 4-4 impact specimens were tested with pendulum impact test machine. The test results show that very high impact toughness is up to 110J .
2.3.4 Hardness measurements
According to GB / T230.1-2018 Metallic materials Rockwell hardness test Part 1: test method, Rockwell hardness tester is used for testing. The test results show that the hardness value of the broken blade is 280-297HB, which is qualified (the qualification standard is 277-321HB).