Patent ID: 7232053
Filing Date: 2007-06-19
Classification: B23K

Abstract:
1. A method of forming a steel structure comprising the steps of: providing a first surface of an air hardenable martensitic stainless steel; providing a second surface of an air hardenable martensitic stainless steel; said martensitic stainless steels having a carbon content equal or greater than 0.08% by weight; positioning said first surface adjacent to said second surface; welding said first surface to said second surface by applying a first heat source to said first surface and said second surface at a sufficiently high temperature to said first surface and said second surface above their melting points to form a weld; applying a second heat source said weld immediately after said step of welding so as to be prior to said weld cooling below the lower critical temperature for said martensitic stainless steels, said second heat source being at a temperature lower than said first heat source but at a sufficiently high temperature and maintained for sufficient long time period so as to reduce the hardness of said weld.