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Up Topic Welding Industry / General Welding Discussion / Ok I got a crack to fix.. Need some input
- - By Kix (****) Date 05-16-2007 20:34
  Ok i have a crack in a shear point on one side of a truck frame channel.  I don't know the ASTM # on the steel but i do have all the goodies so lets see what you guys think it is and how to repair.
It's a heat treated steel
Yield ksi min = 120
Ultimate Tensile ksi min = 125
% elongation in 2" 12
Brinell hardness 269-331
Here's my delima do i match the tensile to a matching filler or do i repair with something thats going to give alittle bit with a lesser tensile.  I'm going with GTAW process with a full penn weld from one side.  It's in a tight spot so i'm gona drill a hole where the crack stops and bevel it with single U groove with a dremel.  Going to keep an eye on interpass temps also. So what do you guys think?

Thanks  Kix..
Parent - By js55 (*****) Date 05-16-2007 20:42
Kix,
Just to start things off.
You sure those numbers are correct?
A .96 yield to tensile ratio with 12% elongation seems out of kilter to me.
If I may, how did you determine those numbers without the ASTM Spec?
Parent - - By DaveBoyer (*****) Date 05-17-2007 03:54
If the frame was made by Dana Corp it is SAE 1027 modified material, acording to the guy who ran the lab there. I have E-mail Him to see if He remembers anything about an alowable weld repair procedure, no promises.
Parent - - By Kix (****) Date 05-17-2007 12:24
  The rail was made in mexico and those were the specs they sent when are engineers asked s thats all i have to go by.  So ddo you think i should try to match the base material as close as possible with the appropriate filler or should i go with something a bit ductile?  I'm thinking since it's in a relaxed state now that a close match to the base material would be sufficient.   All i know is it can't crack again or we have to replace the rail.  No pressure huh!!..
Parent - - By DaveBoyer (*****) Date 05-18-2007 02:33
Kix: I did get a reply from the former lab manager, is there an E-mail adress I can foreward it to for You?
Parent - By DaveBoyer (*****) Date 05-18-2007 06:28
My personal opinion after thinking more about this is that [baring some extremely severe mistreatment by the driver] Your company should start with a new rail and re engineer the motor mounts in such a way that it doesn't cause premature frame failure. How much use has this truck seen? How many units of this configuration have been built? How many do they expect to build? If there are others out there they should retrofit them with an improved mount ASAP.
Parent - - By 803056 (*****) Date 05-17-2007 14:52
Are you sure you want to be involved in the repair of a high strength steel truck frame?

You need to go back to the manufacturer and follow their repair instructions to be in compliance with the federal safety laws. I know a little about the subject because I've been involved in a couple of cases where repairs or modifications have been made. One involved the modification to several brand new trucks that had to be reworked and the other involved a death that is still an open case. One has already cost the contractor many thousands of dollars and the other will most likely involve a settlement of several millions of dollars. I'm glad to say that I was not representing or working for the people that did the welding.

The truck frame is no doubt a high strength quenched and tempered steel. There are strict requirements for the repair of these frames. The first requirement is "DON'T WELD ON THE TRUCK FRAME." It was illegal to weld truck frames until a couple of years ago. Federal laws prohibited the practice even though it has been done for years.

I've said it before, and I'll say it again now, "No one cares until someone gets hurt, then all the lawyers come out of the woodwork to hang your sorry butt."

Are you prepared to loose everything you have ever worked for to save a customer or yourself the cost of replacing the frame rail?

Best regards - Al
Parent - - By Kix (****) Date 05-17-2007 15:47
Well, we build and weld all our own truck frames in most cases.  This chasis in particularcomes in pieces and we drill and bolt it together.  Question is then since i have no astm# and no chemical composition to match it to anything can this stuff be welded?  I think the company allready put themselves at risk when they modified the frame to fit this particular engine and made a shear point.  I'm sure they're going to be keeping an eye on this area from now on after the repair since we guaranteed them a new rail if it starts to crack again.

  Is there any website i can go to that has a way to help me find out what i'm working with here and how it can be welded?  Also is there a place i can go to that has the strict requirments to repair a frame of this nature?
Parent - - By 803056 (*****) Date 05-17-2007 16:40
You should be able to find the website for the truck manufacturer on the internet. The website should list a contact for their technical department where you can ask for technical information such as your "how do I weld" question. You need to have the year, model, and VIN information available.

Most companies have some sort of "Body Builders Guide" that should be reviewed. They usually contain information about welding requirements. Each manufacturer has their own recommendations as to how to weld the frame and how to reinforce the frame. Each manufacturer uses different steels, so each has different requirements for the filler metals to be used and recommended welding parameters.

I would expect the "Body Builder's Guide" to state the welds should be located before the front spring hangers or behind the rear spring hangers. Any welded splice will have to be "fish plated" with body interferring high strength bolts with bolt holes drilled undersized and reamed to provide a tight fit.

Again, federal laws require your employer to follow the manufacturer's requirements. You do not want to be embroiled in legal battle if the welds fail and someone is killed or injured.

Good luck - Al
Parent - - By darren (***) Date 05-17-2007 21:08
hey kix, 803056/al is doing his best to be subtle, its one weld that could destroy your life, and if it is so important to your boss let him do it. i would pay head to al's vast years of experience and accept that they are putting you in a bad way at work by asking you to repair something that is designed wrong. as i say all the time would you want your son/wife friend driving the truck after such a repair was made. just refuse to do it. let them re-engineer it . or at least replace the "whole rail".  basically tell them to stick it up there ass. i am not as subtle as some of the other more gentile types in this forum

kix just say no to them and save yourself the hassle. cause if you succeed at doing this weld they will expect you to do worse and worse things till something catastrophic does occur.
its your life, but depending on your decision it may also be someone else's. we are just concerned for a fellow welders/humans.
darren
Parent - - By 803056 (*****) Date 05-17-2007 22:08
Amen!

Some folks are so much more eloquent than I am!

Al
Parent - By Kix (****) Date 05-18-2007 12:32 Edited 05-18-2007 12:47
Well, i guess i was just under the impression that it would not be my a$$ that gets in trouble, but the guys that said we are going to repair it and the guys that designed the frame so it was under so much load right there with no beef.  I'm also under the impression that after the repair is made their is going to be some stiffining of the frame to keep this from happening again.  I know if we were to just leave it in the as welded condition that there would be a risk on this happening again.  I have faith that with a little more beef in the area that welding on the frame would be ok.  So i was just looking for some info on this matter and i appreciate all your replies and i will take what you have said to me and not touch the frame unless they are going to fix the reason this happened in the first place after it's welded.  Trust me that i would not do anything that could put someones life on the line.  I've allways welded everything that i weld with the attitude that i want to keep all my fellow brothers safe and brothers that have to work on the stuff i have welded on years to come safe and if something happenes it's not going to be because of something i did. 
Up Topic Welding Industry / General Welding Discussion / Ok I got a crack to fix.. Need some input

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