Many folks here on TBN have no idea of how to fix a part by welding and base their comments on their own ability of lack of knowledge of the process.
A properly welded repair to a piece of pipe or structural object will always be stronger than the original part due in part to the electrode normally being rated for higher tensile strength than the part being welded and it is always thicker than the part in the as welded condition when a full penetration weld is made. I have witnessed burst testing on piping with buttwelds on it and the pipe always gives way before the weld.