The Development Of Domestic ENICrMo-4 Electrode Welding Of 9% Ni Steel

This paper reviewed the domestic and international 9%Ni steel with ENiCrMo-4 welding based on the research status of ASME,ASTM,on the basis of USA standard G28 standards,national standards GB/T 13814 and Sinopec group Luoyang petrochemical engineering company of 160000 cubic meters of low-temperature tank project performance requirements,combined with the Shanghai the Atlantic Welding Material Co.Ltd to design and prepare for natural gas industry,9%Ni three kinds of China made ENiCrMo-4 steel welding rod,test and analysis of the composition and mechanical properties of three kinds of electrode deposited metal.Using the above three kind of shielded metal arc welding joint of 9%Ni steel,and the same type of foreign ENiCrMo-4 welding were analyzed,the best formula of the comprehensive performance of electrode were determined;the optimal 9%Ni steel welding electrodes,welding current,the influence of composition on Microstructure and mechanical properties of welded joints.Deposited metal test results show that: three kinds of electrode development conforms to the AWS A5.11,GB/T 13814 standard requirements.But the comprehensive performance of ENiCrMo-4 electrode C optimal.C,Si content were 0.019% and 0.166% ENiCrMo-4 electrode deposited metal of C,P,S and other impurity elements content was the lowest,the tensile strength of Rm is 758 Mpa,the yield strength of Rp0.2 is 497 Mpa,the elongation of A was 35.1%,the hardness is 262.85.The domestic and foreign ENiCrMo-4 welding test show that: compared with 9%Ni steel C welding joint of ENiCrMo-4 welding electrode has the best comprehensive properties,the joints of-196 low temperature impact in the weld center,the fusion line and weld lines at +2mm = 90 J,93.3J,119 J,can meet the requirements of the project of Sinopec tank;through the ASTM G28 corrosion test show that the ENiCrMo-4 electrode,C electrode corrosion resistance is better than that of foreign countries.There is obvious influence to the performance of welded joint of 9%Ni steel ENiCrMo-4 welding current of C welding.The welding current is 130 A,the mechanical properties of the welded joints,spalling resistance and corrosion resistance are the best,the tensile strength of Rm joint 741 Mpa,yield strength of Rp0.2 is 458 Mpa,the yield ratio is 0.62,the elongation of A was 41%;low temperature impact toughness of joints in the weld center,near the fusion line,fusion line +2mm is respectively 89.3J,92 J,94.7.