TWI Industrial Member Report Summary 606/1997
K R Ayres and S T Riches
CO2 laser welding of tailored blanks has become an established technique to achieve weight and cost savings in automobile body manufacture. This report described work TWI has carried out in this growing market.
Tailored blank technology has emerged as a prime means of achieving weight and manufacturing cost savings in steel automotive body structures. The annual worldwide production of tailored blanks exceeds 20 million, with a 50% growth rate predicted. There are four main joining techniques used in tailored blank manufacturing; laser welding, mash seam welding, non-vacuum electron beam welding and high frequency butt welding. Laser welding is attracting growing interest due to its inherent flexibility.
This report describes work carried out by TWI to investigate various aspects of CO2 laser welding for tailored blank technology, carried out in collaboration with British Steel, Rover Group and BOC.
- To determine the effect of process gas and welding speed on formability of CO2 laser butt welds in zinc coated steel sheet
- To optimise CO2 laser butt welding of re-phosphorised steels
- To evaluate CO2 laser cutting for sheet preparation
- To establish the fit-up requirements for CO2 laser butt welds in 0.7 and 0.8mm thick zinc coated steel
- To assess the formability of CO2 laser butt welds in iron-zinc coated steel with surface mismatch
- To complete CO2 laser welding of case study tailored blanks