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).