Article
In industries such as ventilation ducts, home appliances, automobiles, kitchen supplies, and packaging tool boxes, in order to extend the service life of products and enhance the corrosion resistance of materials, coated steel plates are becoming more and more widely used.
Galvanized steel plateResistance spot welding, Projection welding has the characteristics of small contact resistance, reduced welding current density, easy contamination of electrodes on the coating surface, and easy occurrence of crystal cracks, and poor weldability. Therefore, the welding process of galvanized steel sheets is a complex process involving physical heat transfer, metallurgy and mechanics.
Welding phenomena include the heat transfer process during welding, metal melting and solidification, phase changes during cooling, welding stress and deformation, etc. To obtain a high-quality welded structure, these factors must be controlled.
The essential cause of splashing is that the liquid metal breaks through the metal shaping ring, causing the unsolidified liquid metal to splash out, causing solder joint defects and affecting the quality of the workpiece. However, the reason why liquid metal breaks through is mainly due to errors or inappropriateness in the matching status of the base metal, the status of the equipment, and the setting of welding parameters during the welding process.
Coated steel plates include electro-galvanized plates, hot-dip galvanized plates, electro-zinc-nickel alloy plates, hot-dip galvanized iron alloy plates, organic film-coated plates and uncoated cold-rolled plates with various coating thicknesses.
We tested its performance in resistance spot welding as follows: 1) The variation pattern of the projection welding joint strength of various coating materials with the welding current shows three typical upward convex parabolas, approximately linear rising and concave parabolas. 2) The welding current needs to be finely adjusted during resistance projection welding of various coating materials. 3) Comparison of weldability of coating materials shows that: cold-rolled steel sheets, organic film-coated fingerprint-resistant sheets and galvanized alloy steel sheets have good weldability, while oil-coated galvanized sheets and hot-dip galvanized untreated sheets with thicker coatings have the worst weldability, and the weldability of electro-galvanized phosphated steel sheets is lower than that of electro-galvanized untreated steel sheets; (4) The slow-up function of the controller can significantly improve the spatter phenomenon during welding of 90% coated steel plates, and also has a significant effect on improving the mechanical properties of the joints. 5) For small quantities, use a lever foot-operated spot welder, and for large quantities, use a pneumatic spot welder. The electrodes should be replaced with flat electrodes without leaving a trace on the surface of the galvanized sheet.
Wuxi Xinxing Welding Equipment Factory has been engaged in resistance welding for 29 years. Its core technology products include: semi-automatic butt welding machine, pneumatic-flash butt welding machine, multi-strand wire welding machine, foot spot welding machine, pneumatic spot welding machine, medium frequency spot welding machine, row welding machine, mesh welding machine,Resistance automatic welding machine, energy storage welding machine, copper rod and aluminum rod disc circular welding machine, auto parts spot welding machine, sheet metal spot welding machine, home appliance hardware spot welding machine, small electrical appliance spot welding machine, copper row copper pipe welding machine, nut spot welding machine, stainless steel welding machine, foil strip spot welding machine, aluminum spot welding machine, multi-head spot welding machine, bag There are more than 300 types of cage spot welding machines, mesh welding machines, ton rack welding production lines, resistance automatic welding machines, brazing machines, diffusion welding machines, projection welding machines, seam welding machines, wire and cable optical cable supporting equipment, etc. If you are interested in our welding equipment, please contact us.