welding test [MIG]

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I got called about a contract job welding booms for cranes,,,,the process is mig ,,,,,,,, i think they said the wire was a 140,000 tensile strength wire you would be testing on....in the flat,,,,they are having trouble with the bend test,,,,,,,[breaking],,,,,,,,,people are passing the ut's and failing the bend test....i have welded 100 series wire and had no ploblems,,,,,,,we did pre heat though.................what should you keep in mind when taking this test,,,,,,,
Reply:i realize mig welding is very easy and alot of people kinda do not pay attention to angles,and the root passes, and forget to split half the previous beads and half the base metal,long arcs,and all the attention to detail with taking all test,,,,,,i was just wondering if there was something that i was forgeting about, or anyone could add any helpful info on hight tensile stength mig welding wire,,,,the test is on 1 inch plate with open root i belive..i belive also .035 wire,,,,,,,not sure on what type of sheilding gas,,,,,bring the feedback on!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Reply:I'm wondering why they aren't using dual shield flux core for something like this, seems like they would use a process that has a better deposition rate than mig.Lincoln pro mig 180Lincoln Square Wave Tig 300/wp 20/home built water cooler Victor, Purox, Harris, O/A welding/cutting setupsVintage Craftsman drill pressVintage Craftsman/Atlas 12"x 36'' lathe7''x 12'' w/c band saw Everlast 140 st
Reply:Using GMAW is odd to me as well... I don't recall even reading about a solid wire with that high of Tensile Strength... I used to use Hobart Fabco 110 (Dual Shield FCAW) on QT-100 steel.Sorry - Can't be of much help, just thinking out loud.Not sure what "In the flat" is?... 1G Open Root with bevelled plates?Thickness doesn't matter, if your Root Pass doesn't penetrate and have some reinforcement on the back side of the coupons, you are going to bust out on a Root Bend every time.Concentrate on a good Root Pass with an even weld reinforcement on the backside - Slightly more than flush but less that 1/8"Later,Jason
Reply:One thing that jumps out at me, is .035 wire on a 1 inch thick plate! Don't know can you get enough heat out of .035 wire for 1 inch thick material? Myself, I'd feel better with 1/16 inch wire on 1 inch plate.Don’t pay any attention to meI’m just a hobbyist!CarlDynasty 300V350-Pro w/pulseSG Spool gun1937 IdealArc-300PowerArc 200ST3 SA-200sVantage 400
Reply:I have a friend who welds on cranes using high tensile wire like that. I'll put in what little I know from when I was trying to learn enough to do some work with him.Too much heat was a big issue, as well as too little. Preheat, post heat and interpass temps were called out very specifically for the various alloys and were critical for the higher grades of steel from what he was telling me while I was learning. I'd asked why he used such small wire (.035 IIRC) for doing up to 1". He mentioned that much of the higher tensile alloy steels he worked with were heat treated or tempered and too much heat would mess up that balance and the welds would fail in the HAZ. The smaller wire allowed him to keep the heat input down. It was a fine balance between having enough heat to get a good bond, and yet keep the heat low enough not to damage the grain structure of the metal..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:Originally Posted by DemonSpeederI'm wondering why they aren't using dual shield flux core for something like this, seems like they would use a process that has a better deposition rate than mig.