It is true. There was too much welding on one side at one time. what you should do is spot weld the plate there and then do ice welds on it.
Jul 23, 2010 Rating
BENDED PROBLEM by: JIM
NEVER GET THE METAL THATIT BENDS THE PLATE, BUT NEXT TIME MAKE A SADDLE FOR IT ONE AT THE TOP AND ONE AT THE BOTTOM. A SADDLE IS A PLATE ABOUT 6 OR 7 INCHES LONG AN RIGHT IN THE MIDDLE OF PLATE ON ONE SIDE OR THE OTHER BURN A HALF MOON JUST A 1/2 INCH BIGGER THAN THE WELDED AREA. TACH IT TO WHERE YOU ARE GOING TO WELD, THAT SHOULD KEEP IT FROM BENDING
Jul 05, 2010 Rating
Convex Fitting by: Anonymous
I read a lot of good sugggestions but not much on the fitting. I often exaggerate the fit. I have used a 1/4" to 3/8" round stock in the pass to create a small convex look near the weld seem. Rolling the stock inboard or outboard, depending on the thickness and length of the base metals. This effects the amount of weight on the ends, so as the weld shinks the weight helps the two planes become one. Not forgetting to walk short staggerd beads. I use a rosebud and clamps as needed and not as a matter of course. A good straight-edge like a length of angle with a small piece of stock tacked on at each end lifts it over the weld so measurments can be made quickly and easily. Your weldment will shink and warp regaurdless of what you do. Stop, look, and listen. As it speeks answer.
May 22, 2010 Rating
Reply by: Jim
As I said before, I can't even attempt to offer advice for correction. The original post does not give enough information to even guess. To make an attempt I would need to know: 1. Base Metal type
2. Filler Metal type
3. Joint Type
4. Dimensions of Base Metal
5. Joining process (MIG, Stick)
Just to name a few.
And by the way, when doing heavy plate welding it is impossible to stop all weldment distortion. You can control it to a point. And when using strongbacks there is the concern of excessively restraining the joint against transverse movement as the weld shrinks, and thus increasing the possibility of weld cracking. It would also help to understand compressive stresses and tinsile stresses resulting from the welding process. If anyone has any questions they can ask.
May 22, 2010 Rating
revision by: Anonymous
you can clamp the plate on all four corners, or near the corners. You could tack backing bars perpendicular to the backside of the plate, use the backstep welding method while skipping around making small welds on different joints. Use a heat sink on the bottom of the plate, like a thick piece of copper, or brass. I left the comment about the plasma grinder, as a joke of course, but I hope any of these tips help....depending on how many you have to make you could always make a jig with quick clamps as a part of it.
best of luck
matt
May 22, 2010 Rating
great advice jim by: Anonymous
Jim your a great critic, but if your that good how about give your advice.
May 20, 2010 Rating
helpful tips and tricks by: Anonymous
as a welder of many years and completing many jobs, I have found if you utilize a plasma grinder and or a plate stretcher, it will negate this problem.
sincerely,
matt
May 20, 2010 Rating
Inexperience by: Anonymous
My best guess is that your people were doing a dual shield weld on that plate. 2" thick plate, or anything that thick has a vary narrow weld zone. I have to assume that it could not have been too leangthy or it would not have crowned on you. Pre-heat is a good thing but if you pre heat to 300F (150c) you may not be able to get close enough to weld it in the first place. Pre heat is good for cast-iron. but not so hot you can not work with it. The guy who said to v grove both side of the plate is the closest to the mark. Any thing that think need the double v groove weld so you can have the penitration you need. Make single passes on both sides and let cool. Heaving welding at one time will effect the grain, heck any heat effects the grain and changes the metal structure. I would sugguest that you get a book on metallurgy and look at the metallurgy of welding. Clamps are a big help and depending on what you need the metal to be after wards you might want to consider on your cooling technique. Adding water can help if you dont mind it becoming brittle and it wont take too much of a beating afterwards. Slow cooling is what i go for in most of my welds to allow the grain structure to get as close to base metal structure as possible. However it is never possible to get it back all the way no matter what you do because all heat will change grain structer every time. In your case, clamp it down or weld it down and let it cool completly before making another pass. Slow and steady wins the race and saves you money.
May 19, 2010 Rating
v groove/ pre heat by: Anonymous
Its hard to answer if you havent seen it. BUT, If your BUTT welding the plate, V-Groove both sides of both plates,per heat and weld one side then weld the other side back and forth.
May 19, 2010 Rating
bending plate by: peter james
yes the problem is over heating what you need to do is, weld some angle iron from corner to corner and then cut them of after it will help it to stop bending from the heat.you could also try welding about 1 inch at a time start top then to the bottom and keep doing this until you reach the middle.but give it time to cool of before you finnish i use a wet cloth.
May 19, 2010 Rating
weilding tip by: paul cashell
if you get a length of heavy gauge steel and g clamp to your work piece with as many clampa as needed and alternate your weilding from left to right. this allows each side to cool slightly and prevent heavy warping. its good a bottle of cold water there beside you to pour on after every 100ml and wipe dry before you commence wielding. this has worked for me. hope this is a help to you.
May 18, 2010 Rating
You Have Got To Be Kidding Me by: Jim
Is there anybody in here that is not guessing and actually knows what they are talking about. First of all, the first post did not give nearly enough info to even attemp to guess at a solution to the problem. Second, even the guesses were clear out in left field and were a clear indication that nobody has a clue as to what they are talking about. Are there any REAL fitters or fabricators in this forum? Sounds like a bunch of inexperienced weldors that don't know the first thing about weld theory or what acually happens during the welding process.
Apr 11, 2010 Rating
old school by: Anonymous
ya you need to strong back it and back steping will help alot thats wwhere you stop on your starts
Apr 11, 2010 Rating
Distortion by: Anonymous
Without seeing the workpiece certain assumptions have to be made but in general any welding in steel will cause distortion the trick is to even out the distortion by preping the plate (in the case of a but weld) from both sides and alternating between in multipass welds. To pull back the distortion try veeing out the opposite side and rewelding. next time try arresting the contraction with clamps.
Mar 09, 2010 Rating
kinda like stiching by: ricky robot
i dont know how long yor welds are,it sounds like you are running some long welds. if so trystaggering your welds.2" is also borderline preheat.
Jan 28, 2010 Rating
Pre-Heat by: Brad Hazlett
Sorry, don't forget to preheat and post heat.
Jan 28, 2010 Rating
Braces, clamps and heat by: Brad Hazlett
You must use braces, clamps and or hydrolic presses to hold the steel in place. Im going to say that you had a single-v groove or single bevel. You must run your root pass first to much heat will cause the plate to warp but being 2"s thick it should'nt warp on your first pass, you must run your passes at a slow and controlled temperature. Under ASME and AWS codes it will specify the heat range so that warping and the charicteristics of the metal are not changed. You should not exceed 500 degrees for steel but can be fluctual but not recommended. Use a heat gun or heat tape. Take your time and make sure you have the right setup and everything should work out great. If its only a butt joint just make sure you have it secured in place and run half plate on one side and run full length on other side. Hope all works out.
Brad (Newkensington)
Jan 27, 2010 Rating
Put strong backs by: Anonymous
Put strong backs on the back of the weld and attache them with atleast one inch long thick weld..
Strong back is like a Small bridge kinda shapped piece of metal looking some like this :
\_/-\_/ where the too bottom ends are welded to either plate and the center gab leaves the space for it not to effect the weld itself
Hope this kinda makes sence...
Sep 23, 2009 Rating
Do lots of small welds by: Anonymous
Whoever told you that you welded too much at once was right. You haven't to do on continuous weld. Instead you do lots of small weld alternating from one side of the weld to the other so the metal can stay as cool as possible. Its the heat that warps the metal. Do two inch or once inch welds at a time.
ALAN
Aug 27, 2009 Rating
My Idea by: Jenna
I believe what you should have done was use giant clamps and jump from one side to the next. It might bow a bit but not much or not at all.
Aug 17, 2009 Rating
the pot belly effect by: E-nasty
if your weld is thicker than 1/4 round off the edges and have it as ovuler as you can with out ruining the size of the piece.
Jul 18, 2009 Rating
mcwelder by: brent mcnamara
use as little heat as possible [turn the welder down as low as you can and still achive a good weld] and dont weld hot on hot allow time to cool
Jun 30, 2009 Rating
distortation control by: Anonymous
welding distortion is caused by the heat involved in the welding, when welded the area first expands a little but contracts more upon cooling causing the plate to bend. Preheating the weld structure opposite the side being welded helps alternating beads and large rods to reduce the time heat is applied also help.Pluse welding with mig will cut the total induced heat time. Ridgid clamping of the stucture to be welded helps and a stress rellieve post heating will also help.istition control is a big issue on many weld applications and text books have been written on this. Check with The American welding society and you can probbaly download the recommended procerures. This is a bigfield.
May 07, 2009 Rating
Bevel ? by: Cory The Welder
I always heard anything over 1/4 thick should have a bevel. Preheat is important on something thick.
May 06, 2009 Rating
trouble solution by: Anonymous
yes, it happens when you weld a thick plate.
it has two solutions.
1. pre heat the plate at about 150C and then weld
2. use the altenate weldind technique, i.e, 1st apply a pass from one side of the plate and then invert it and apply the next pass from the other side. repeat the same technique,you will get out of troble
May 04, 2009 Rating
common problem by: Anonymous
This is a common problem in all metal.
One area can heat up and expand before another area resulting in warpge. To see this on a smaller scale take a small flat piece of sheetmetal and heat the middle with a torch. WHat you should get is a cuped piece of steel since the middle will want to expand. You can reduce this by welding in one area going to another and skiping around to avoid large amounts of heat buildup in one area.
May 04, 2009 Rating
Yes, it is by: Anonymous
It is true.
The forces involved in metal dilatation or contraction by temperature they are ENORMOUS. A little welding point cede, but a large cordon maybe not.
