Chrome-molybdenum tube cracking at Boston Navy Yard

Brief callback. The Navy insisted on Inconel rather than stainless steel for chrome-moly tube welds because, after ten-thousand-hour service, stainless steel forms brittle topologically-close-packed (sigma/mu/Laves) phases. Tom uses the case to illustrate that the TCP brittle-phase problem is not merely academic — it shaped a real Navy specification.

That may have been one of the problems we had with my chrome-moly tube over at the Boston Navy Yard. They wanted me to say, yeah, you can use stainless steel to weld it, but the Navy said you had to use Inconel. It turns out the stainless steel probably, after ten thousand hours, formed this brittle phase, and the things would crack. So it's a general problem.