A Laser Tailored Welding Method for Thermoformed Steel with Al-Si Coating

Abstract

The invention provides a tailored blank laser welding method for hot-formed steel with Al-Si plating. The method comprises steps as follows: tailored welding is performed on a hot-formed steel plate with the Al-Si plating under the condition of shielding gas by laser welding equipment; and the shielding gas includes mixed gas of one or two of oxygen and carbon dioxide and inert gas. In the tailored welding process, the mixed gas of one or two of the oxygen and the carbon dioxide and the inert gas is used as the shielding gas, the oxygen partial pressure in a welding pool is increased, Al and O elements entering the welding pool are combined to form Al2O3 which does not affect the strength and toughness of a weld joint, Al and Fe elements are inhibited from forming an intermetallic compound and affecting austenitic phase transformation, a weld joint zone with the all slat martensitic structure is obtained finally, and the strength of the weld joint reaches the level of base metal. With the method, welding wires are not required to be added, plating removal before welding is also not required, the method is simple, the production efficiency is improved, and the production cost is reduced.

Description

technical field [0001] The invention relates to the technical field of laser welding, in particular to a laser tailor welding method for hot-formed steel with Al-Si coating. Background technique [0002] With the increasing number of cars in the world, a series of problems such as energy shortage and environmental pollution have become increasingly prominent. Energy saving and emission reduction has become an urgent problem to be solved in the world automobile industry. According to statistics, if the weight of the vehicle is reduced by 10%, the fuel efficiency can be increased by 6% to 8%. For every 100 kg reduction in the curb weight of the vehicle, the fuel consumption per 100 kilometers can be reduced by 0.3 to 0.6 liters; if the weight of the vehicle is reduced by 1%, the fuel consumption can be reduced by 0.7 %. Ultra-high-strength steel has obvious advantages in terms of anti-collision performance, processing technology and cost, and can meet the dual needs of reduc...

AI Technical Summary

Problems solved by technology

However, this method is to achieve welding by adding welding wire. Obviously, for practical applications, it is precisely because of the use of welding wire, the addition of wire feeders, the matching of laser beams and wire feeders, etc. that the production cost is significantly increased.