工程机械专用高效CO2气体保护焊焊丝的研制-材料加工工程专业论文.docxVIP

Research on Special High Efficiency wire of CO2 Gas Shielding Arc Welding for Construction Machinery ABSTRACT The use of CO2 gas shielded welding occupies approximately 70% in producing steel structure of construction machinery,with equipments popularization and mature manufacturing technology,welding productivity of steel structure is the key factor of the development of enterprises and improving product competitiveness.According to the domestic situation of construction machinery,ER50-6 is the most widely used welding wire,so develop a new wire with same strength standard 、 higher weld efficiency 、 less spatter and better formation of weld by adding trace alloy and chemical composition optimization has good practice value in engineering. Exploring reasonable chemical composition of new wire by the method of welding in the area where adds mixed trace alloy powder,then ascertain the composition area of this new wire rod.Test the physico -chemical performance by using direct-reading spectrometer,optical microscope,micro-hardness tester, universal material testing machine. After husking 、 drawing and copper electroplating processes rod is made into wire,do welding procedure test and analyze the mechanism of trace alloy elements on weld ing spatter 、 welding penetration and welding arc etc.The results show that:(1)It can effectively increase the welding penetration depth of more than 50% by adds mixed trace alloy powder into welding area.(2)With the adding of alloy elements the drawing performance of wire rod didnt be deteriorated and there are not cracks 、dents、sharp edges or the other defects on its surface;the microstructure is fine and uniform in hot rolling or annealing condition.(3)Compared with normal ER50 -6 welding wire, welding technological properties is better by using new wire in the same welding parameters,welding spatter loss coefficient is low,welding gap is more beautiful and the penetration is deeper.