Find Stainless Steel 1 3 16 In Gothic at Amazon
|
What are the best proficiencies for welding stainless steel? That’s like asking what is the best way to go fishing? It depends on a lot of things, doesn’t it? Lots of things like what type of stainless, what thickness, what is the application, and for what industry? Lets focus on three industries: Food service, Aerospace, and Nuclear. 1. Food Service Most stainless steel in the feed service industry is 300 series stainless. Type 304 .063″ thick stainless sheet metal to be exact. If you go to any Fast feed counter and check out all the counters, shelving, cookers and such, you will detect it is all made from welded stainless steel sheet metal. Food service codes require 304 stainless steel to be applied in feed preparation areas because it does not rust easily. All welds are supposed to be performed in such a way to not trap bacteria and other crud. Back sides of stainless steel welds will have to be shielded with argon so that they are not sugared and full of pits that could trap bacteria like salmonella. All wire brushing will have to be done with a stainless steel brush and welds that are not perfectly smooth must be blended smooth with a great deal of type of abrasive wheel and then cleaned with alcohol. Tig welding is closely always the best procedure since spatter and slag are absent. Tig welding rods must be 308L for welding 304 stainless. L is for low carbon because Carbon is bad when it comes to corrosion resistance in stainless. Tips for welding SS sheet metal : 1 amp per 1 thousands of thickness, keep the hot tip of the filler rod shielded and snip it if it gets oxidized, use chill bars made of aluminum, copper, or bronze whenever possible. Filler rod ought to in general not be more prominent than thickness of metal welded. Keep bead width to around 4 times the thickness of the sheet. Use a gas lens style cup, a #7 or bigger. A 1/16 thoriated or lanthanated electrode will without apparent effort weld 16 ga .063″ sheet. Keep electrodes clean and sharp. 2. Aerospace Stainless steel alloys employed in the aerospace and aviation industries are a bit more varied. There are lots of them. Austenitic stainless steels like 321, 347, 316, and 304 are common, but so are martensitic stainless grades like 410 steel , Greek Ascoloy, and Jethete M190. Another family of stainless employed on mercantile aircraft is the Precipitation Hardening variety. A PH at the end like 15-5ph, 17-4ph, 15-7ph, 17-7ph gives evidence of that the steel is precipitation hardening. That means keeping it at high temperature for extended time allows the steel to harden. PH grades are on occasion much more difficult to weld than the straight 300 series because of alloy elements and complex metallurgical reactions to heat while welding. Tig Welding and automated plasma welding are the most commonly employed processes. Tips for Aerospace tig welding SS : Clean, Clean, Clean. Use as big a tig cup and possible 3/4 ” –1″. Use minimal heat and use any means to prevent distortion (skip welding, fixturing, little beads) shield the back side of everything you weld with argon using tooling, or home made purge boxes. 3. Nuclear Nuclear piping schemes use a lot of stainless steel and most of it is TIG welded. Or at least the root pass is tig welded. Most of the stainless piping is basic 304L stainless but other grades like 316 are used also. Tig root passes with stick fill is beauteous mutual with heavy wall pipe but anything underneath schedule 80 is commonly just Tig welded all the way out because x ray results are better that way. Stick welding is kind of hard with stainless. Instrumentation lines that are 1/2″ and less in diameter and are oftentimes done with orbital tig welding because it is so repeatable. Welding little diameter tubing manually is tough. There are all kinds of other apps for welding corrosion immune alloys like boat propellers, headers and exhaust, and marine hardware like sailboat parts. One thing to do not forget is that they distort without apparent effort so precautions like heat sinks, chill blocks, and minimizing heat input are all crucial proficiencies to use.
|
