4130 tig vs mig

[Oppet]

Hi all

I have Husqvarna frame thats 4130, welded with Mig

I thought 4130 would be only with gas or tig, but then they sell these from factory.
Why gas or tig is better here or why it is the recomended style?
will i get lifetime warranty from husqvarna if they have a manufacture fault

T

 

[pedrobedro]

Why would Husquvarna maufacture something in a way which they thought was unsatisfactory ? They will not be welding the frames in a shed with a welder from ebay and 10 minutes practise so I would not worry about anything but I don't know any firm who would offer you a lifetime warranty with no conditions on use of the product.

 

[hotrodder]

4130 predates the invention of TIG (and so MIG too) by a good few years. The issue with welding the stuff is the potential for hard, brittle welds and HAZ. That one can be fixed through wire/electrode selection and/or preheat and post weld heat treatment. Back in the day O/A would be the method of choice for say a thin wall tube frame using a mild steel wire to get a good balance of strength, toughness and ductility. Parts that'd be heat treated would require pre and PWHT and a higher strength wire. If pre and post heating then stick welding could also be used where appropriate, the extra hassle of pre and PWHT not an issue that'd influence choice of process

If the internet is to be believed a lot of the stuff that gets spouted about MIG not being suitable may be to do with NHRA as they've mandated TIG only. There's several stories behind that decision... some along the lines of this article http://www.netwelding.com/Welding%204130.htm others based on nothing more than the theory that the safety guys (and established chassis builders) didn't really want DIY types building topfuel chassis and at the time TIG was beyond the reach of most DIY types

As said, you'd think they've sorted out the potential welding issues during R&D and decided that they could produce a satisfactory product faster/cheaper using MIG

 

[KemppiFrog]

Just to add: I got involved in a kit plane project and the tube was 4130 IIRR. All MIG welded from the factory. Around '98. So not that long ago. It was not what I would call tidy welding. But didn't come apart in the one I used. (The plan was to build them under licence) So the EEA in the US were happy about MIG, even if the NHRA weren't.

 

[RMX]

I think Husky wont give warranty because it is a sports motorcycle for competition use.
They Mig weld it because it is faster and it will make the manufacturing process more economic.
If done right Mig is as good as Tig.
All offroad motorcycle-frames that I have seen were Mig welded.