Research And Optimization Of Laser Welding Process Parameters For Cold Rolled Strip

This paper relied on the author'sexperience and convenience of working on laser welding in Ansteel cold rolling factory,first systematically expounded the application and research status of the laser welding of cold rolled strip,briefly introduced the technology and application of Miebach laser welding machine.Combined with the historical application of laser welding production process in Ansteel's three cold rolling production lines,the main defects and causes oflaser welding were analyzed,and the welding quality inspection methods were introduced.Revolving round5 key process parameters directly affecting the welding quality,including the laser welding speed,welding power,protective gaspressure and flow,cross-air flow,preheat power and postheat power,under ordinary steel condition the paper made a theoretical research and established general relationships between the process parameters and the quality of theupper and lower surface,punching performance of welding seam,the different factors of laser welding process parameters affecting the weld qualitewere analyzed.The theoretical analysis and experimental conclusion of single parameter setting of the laser welding were presented,where are generally applicable to the production sites of most kinds of steel.The parameters of the laser welding process,such as th e welding speed and so on,have established the general relation of the parameter selection.The parameters of the cross-air flow and other parameters had been proved to be the optimal value of universal application.Through the accumulation of actual production data and experimental demonstration,laser welding process parameters table for various specifications of strip steelwas formed.The level 2 control systemwas used to regulate and automate the process parameters,therefore the process parameters could be adjusted in real time,and the accident of shutdown of the unit was reduced and the production ratewas increased.The influence of carbon equivalent and alloy composition on the welding of high strength steel was analyzed.On this basis,laser welding process parameters of high strength steel were optimized,different combinations of process parameters were tested,performance analyses of welding area were analyzed through Metallographic analysis and hardness tests,actual strip welding experiments and punch testswere made,and the best welding parameters of different steels with high strength steel were obtained.The welding quality of high strength steel had reached the requirements of the unit,and the stable production execution of the high strength steel contract was guaranteed.