Patent ID: 6336583
Filing Date: 2002-01-08
Classification: B23K

Abstract:
A method for creating in a welded joint between two pieces of steel a separation between a heat-affected zone and a toughness weld toe such that a crack formed substantially at said toughness weld toe propagates through one of said pieces of steel instead of through said heat-affected zone, said method comprising the steps of:a) forming a strength weld between said pieces of steel by joining said pieces of steel using a first fusion welding process and a first weld metal, thereby creating a first fusion interface between said first weld metal and each of said pieces of steel; and b) forming a toughness weld by depositing on said strength weld a second weld metal using a second fusion welding process, said toughness weld covering a toe of said strength weld at the junction of said first weld metal with one of said pieces of steel, said toughness weld creating a second fusion interface between said second weld metal and said one of said pieces of steel, wherein said second fusion interface, i) has a width between said covered strength weld toe and said toughness weld toe sufficient to cover at least the width of the heat-affected zone on the surface of said one of said pieces of steel created by formation of the strength weld, and ii) forms an angle of greater than about 45 degrees and less than or equal to about 90 degrees with a plane perpendicular to the direction of maximum tensile load across said welded joint.