I'm also a welder, having worked as a fabricator and pipefitter for E.& J. Gallo in the world's largest winery for several years, where we ran 4" stainless tubing, fitted and TIG welded in place by the mile. Heating and cooling over repeated cycles will stress any type of metal, including crankshafts. One of the first checks an engine machinist makes before regrinding a crankshaft is to suspend it on V-blocks at each end, and check a main bearing journal near the center for runout. Minor problems can be dealt with by straightening. A severe bend is grounds for discard. Even with assembly jigs, some weldments have to be scrapped due to distortion, while others can be straightened by judicious heating and bending, right? Nothing different in the crank straightening business!
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!