ArcelorMittal’s patented partial ablation technology was developed to ensure that hot stamped laser welded blanks (LWBs), made from the latest press hardenable steels (PHS), are as safe as possible. Although it was first used industrially in 2007, the patented partial ablation process is proving more popular than ever with carmakers. It is now used by numerous carmakers and has led to dramatic improvements in lightweighting and safety. By 2020, ArcelorMittal expects the technology will have been used to produce more than 70 million PHS LWBs using ablation technology at locations around the world.
PHS are typically supplied with an aluminum-silicon (AlSi) coating which protects the underlying steel during thermal treatments and prevents corrosion. ArcelorMittal’s patented partial ablation process removes a thin strip of the AlSi coating on the edge of the blanks before they are laser-welded together. If the coating is not removed before laser welding, the aluminum it contains can weaken the weld and cause the part to fail. Around 99 percent of the PHS LWBs made today utilize AlSi coated steels.
source : https://automotive.arcelormittal.com/news_and_stories/news/2019ablationtechnology