Welding stainless steel to mild steel
Welding stainless steel to mild steel
(OP)
I want to replace a 4 inch threaded thru-deck corroded steel fitting (see attached photo) with a similar sized stainless steel NPT fitting used as an access for the emergency tiller arm on a 50ft motorized landing craft. Can a stainless steel pipe coupling be welded to a steel deck without short or long term consequences? If not what are my options? If so please specify the method.
Regards,
Regards,





RE: Welding stainless steel to mild steel
RE: Welding stainless steel to mild steel
RE: Welding stainless steel to mild steel
Drill out the center of the plug and collapse it. Replace in-kind with carbon steel and apply a protective coating.
You can go with an austenitic stainless steel fitting, but this seems like more effort. If you decide to use a stainless steel fitting you need to fillet weld using an E309 stainless steel filler metal. Seems like more work than is necessary.
RE: Welding stainless steel to mild steel
RE: Welding stainless steel to mild steel
I'm in charge of purchasing rod for my company and we used Lincoln rod for, god, 30? years. Then the rep stopped by, I ran some passes of their various rods, he gave me some 10# samples of a couple I was interested in, and within a month all the foremen were asking for more of it. Their rods are a little on the pricey side but they're just amazing to run. The one thing you have to be careful of though is that if your weld calls for a AWS classified rod, some but not all of their alloys are classified. For instance, they have a rod that is a low hydrogen, 75,000# psi, similar composition to a 7018, but isn't classified so it can't be used for things like state certification tests.
RE: Welding stainless steel to mild steel
I have been down this road many times. Stick with AWS classified weld rod and electrodes. Yea, I have heard of magic weld rod that a welder can use with no cleaning, in water, in mud, etc. I have heard it all.....
RE: Welding stainless steel to mild steel
I've been down this road many times myself, and welding with this rod for quite a few years without problem, but keep in mind Cronatron is a big outfit, not a fly by night manufacturer. I'm not claiming this is the 'magic rod' stuff, it's just really really good high quality rod. It's not that it can do things other rods can't, it just produces a really friggin nice weld and when it comes time to do break tests or acid etches on it, they're just flat out beautiful.
As I said, if you know you need AWS classified rod, use stuff that is classified, if you are in a position for shop welding or a repair that doesn't need a WPS, this stuff is the cats meow. And its not just sales pitch, I can say it having used it for years and having done VT, UT, MT, and destructive testing on them.
RE: Welding stainless steel to mild steel