Diffusion surface alloyed metal exhaust component with welded edges

An exhaust component for a motor vehicle, comprising:

• a housing including at least one outer wall defining an internal volume of said housing;
• said at least one outer wall having an inside surface facing said internal volume of said housing and an outside surface facing an external zone positioned outside of said housing;
• at least one inner wall positioned in said internal volume of said housing that defines an exhaust chamber within said internal volume;
• at least part of one of said outer and inner walls being made of a diffusion surface alloyed metal sheet comprising a secondary metal that is formed to a primary metal substrate by diffusion;
• said diffusion surface alloyed metal sheet including at least one exposed edge that terminates in and is exposed to said internal volume or said external zone;
• and
• a weld bead extending along and covering said at least one exposed edge of said diffusion surface alloyed metal sheet such that said primary metal substrate at said at least one exposed edge of said diffusion surface alloyed metal sheet is protected from exposure to said internal volume or said external zone by said weld bead, wherein said primary metal substrate has a primary metal chromium content and said secondary metal has a secondary metal chromium content that is greater than said primary metal chromium content, wherein said weld bead is made of a filler metal that has a filler metal chromium content that is greater than said secondary metal chromium content.

An exhaust component for a motor vehicle, comprising:

• an internal volume;
• an inlet disposed in fluid communication with said internal volume for receiving exhaust gases;
• an outlet disposed in fluid communication with said internal volume for expelling exhaust gases;
• first and second walls joined together at a weld seam;
• each of said first and second walls being made of a diffusion surface alloyed metal sheet comprising at least one cover layer of secondary metal that is formed to a core layer of primary metal substrate by diffusion;
• said primary metal substrate in said core layers of said first and second walls having a primary metal chromium content;
• said secondary metal in said cover layers of said first and second walls having a secondary metal chromium content that is greater than said primary metal chromium content;
• and
• a weld bead positioned between said first and second walls that joins said first wall to said second wall at said weld seam, said weld bead containing a filler metal having a weld bead chromium content that is greater than said secondary metal chromium content of said cover layers in said first and second walls.