USS Sea Wolf submarine high-side weld chemistry and HY-100 cracking

Sea Wolf welding wire chemistry was on the high side of every alloying-element range, producing weld metal that behaved like HY-130 rather than HY-100. Cracking resulted. Repair required 400°F preheat with welders in cooled "blue jelly suits"; $500K hull required $2B repair.

In fact, when they redid the Sea Wolf in the early 90s, the problem with the Sea Wolf is they were using HY-100.

Student: Which is what composition?

Same as HY-80, just tempered at a lower temperature to retain a little more strength. But the weld metal was much higher, and it was on the high side — all the alloying elements were kind of high. You have a range for each alloying element; the carbon might be between 0.08 and 0.16. Well, what did they have for the carbon? It was 0.15 — is that the high side? The chrome was supposed to be 0.2 to 0.3, and it was 0.29. Every heat of steel that they made the welding wire out of for the first 18 percent of the vessel was on what we called a high-side chemistry, and it was really more like an HY-130. They should have been doing HY-130 welding procedures, because the weld metal was basically HY-130, and that's why they got cracking. That and some other things which we can talk about later. But that's why you try to keep your alloy content down as low as possible — to save money and to make welding easier.