In order to verify the qualification of the transverse bending test of 9 Ni steel welding specimen

SMAW is adopted for multilayer and multi-pass welding of 26 mm thick 9 Ni steel. The microstructures and mechanical properties of welded joints are analyzed by Vickers microhardness tester and universal tester. The results show that there are four good transverse bending test specimens

the microstructures of HAZ are martensite and grains are easy to grow. According to the results

the causes and prevention methods of cracks in the transverse bending HAZ are analyzed

which has certain guiding significance to the implementation of welder certification examination standard in classification society.