Q235Steel Welding Joint Organization Structure On The Properties Of Weld Corrosion Impact Study

The SMAW welding and TIG welding and CO2gas shielded welding three kinds ofwelding methods on Q235steel welding, studies three kinds of welding methods afterwelding the corrosion behavior of the sample in3.5%NaCl solution. By electrochemicalmethod to test the different temperature, different methods of sample, and the corrosion rateof different part of welded joint specimens, discusses the corrosion rate of different reasons,to obtain three kinds of welding methods in corrosion in3.5%NaCl solution. Using themethod of testing the samples of the different temperature, different method and the corrosionrate of different part of welded joint specimens, further verify the test results ofelectrochemical method. Microstructure analysis for corrosion microstructure, to determinethe effects of the microstructure and defects on the corrosion rate. Using scanning electronmicroscopy (sem) obtained the microstructure after corrosion, intuitively get temperature,method and effect on corrosion rate.The results prove that:(1) at20℃and40℃, SMAW welding seam and heat affectedzone, the TIG weld and heat affected zone, CO2gas shielded welding heat affected zone andparent metal corrosion rate increases, but after to40℃, the corrosion rate decreased. At20℃and40℃, CO2gas shielded welding seam in corrosion rate is reduced, and after to40℃, thecorrosion speed increase.(2)20℃~60℃, CO2gas shielded welding weld corrosion rate ofthe youngest, the most corrosion resistance weld. And the temperature above60℃, the TIGweld corrosion rate, minimum weld the corrosion resistance.(3) the SMAW welding seamand heat affected zone and the base have appeared in the process of20℃~60℃under thesame temperature range the corrosion rate of weld is greater than the corrosion of heataffected zone, the corrosion rate of speed greater than the parent metal. The TIG welding of20℃~60℃when the corrosion rate of weld is greater than the heat affected zone is greaterthan the parent metal. Temperature of60℃, the TIG welding heat affected zone of thecorrosion speed is greater than the weld is greater than the parent metal. CO2gas shielded arcwelding in the process of20℃~60℃, the speed is greater than the parent metal corrosionof heat affected zone is greater than the weld. Temperature of60℃, CO2gas shieldedwelding heat affected zone of the corrosion speed is greater than the weld is greater than theparent metal.