In order to verify the welding adaptability of domestic welding materials and 9 Ni steel in automatic submerged arc welding technology

domestic 9 Ni steel plates with thickness of 12 mm and 20 mm and three welding parameters（large

medium and small heat input） are selected to complete the welding technology tests of 9 Ni steel in the horizontal position of automatic submerged arc welding.By verifying

analyzing and arranging the microstructures and mechanical properties（including tension

bending

low temperature impact

CTOD and DWTT） of welded joints with different welding parameters and plate thicknesses

the performance test report of automatic submerged arc horizontal position welded joints of domestic welding materials and 9 Ni steel is obtained. Each index meets the requirements of standard specifications and verifies the welding adaptability and matching between domestic welding materials and 9 Ni steel plate.