News & Technicals

Introduction of High-strength Hot-formed Steel Plate Nut Projection Welding Machine

Due to the ultra-high strength and extremely high mechanical safety of high-strength hot-formed steel plates, they are increasingly used in the automotive industry. The use parts are concentrated in the front/rear bumper framework, A-pillar/B-pillar, and Key parts such as the central aisle and front and rear door anti-collision plates, these parts have nuts and bolts that need projection welding; nut projection welding machine is the choice for projection welding of body parts due to its short welding time, small heat-affected zone, and high efficiency. The welding of high-strength hot-formed steel plates with nuts and bolts also uses resistance welding equipment.

Due to the huge welding pressure and very high peak current during projection welding of high-strength hot-formed steel, the requirements for electrode materials during welding are very high, requiring higher softening temperature, higher conductivity and higher hardness. Dispersed copper (alumina copper) has these advantages (softening temperature up to 950°), making it the most suitable electrode material for projection welding of high-strength hot-formed steel plates;

Commonly used materials for positioning pins are bakelite, ceramic, KCF, etc. In recent years, European and American car companies have used silicon nitride as positioning pins for projection welding of high-strength hot-formed steel plates, because of their longer service life (200,000 cycles) and insulation. Good effect, high hardness, etc., make it the new favorite of projection welding positioning pin materials, but because of its high price, it is not widely used at present, but this is the direction of the future positioning pin.

Due to its physical properties and the use of hard standard welding during projection welding of high-strength hot-formed steel plates, the probability of metal extrusion is relatively high. The method of blowing from the bottom electrode can be effectively improved. During welding, use larger air pressure to blow the welding area , Can quickly oxidize and burn the extruded metal, greatly reduce the adhesion of the extruded metal, and ensure the screw thread