350x Frames

**The Goat** · 02-02-2009, 07:19 PM

Okay guys, been dabbling in Industrial Engineering lately at school...and they pointed out some simple metalurgical properties that could affect these frames.

Welding on a frame instantly creates weak points by heating the metal very quickly...and causing it cool very quickly.

Take an average frame...heat it up to 800 degrees...and then slowly bring it back down, and you can completely change the way that frame absorbes stress.

Kinda makes me wonder if honda bothered to heat treat their frames post assembly... Not doing so would cause it to be brittle.

It also brings to mind the question wether all this outgassing during powdercoating, and the powdercoating itself, is changing the strong and weak points of these frames.

Any metal workers care to elaborate on this?

Seems like there's a magic number for rigidity and strength....

**The Goat** · 02-02-2009, 08:58 PM

come on now guys, 20 views and no ones got a thought?

same principle as when making a knife...heat it really really hot, cool it really really fast.

**SWIGIN** · 02-02-2009, 09:18 PM

no matter what you do a stock frame is paper thin (compaired to a chromoly frame) and it will fail.

PC is only cooked at 400 degrees so i dont think that realy amounts to anything

**daniel_250r** · 02-02-2009, 09:22 PM

i think its mainly metal fatigue that makes them crack just being jumped and have force on them after 20 some years they just fail

**The Goat** · 02-02-2009, 09:37 PM

Originally Posted by SWIGIN

no matter what you do a stock frame is paper thin (compaired to a chromoly frame) and it will fail.

PC is only cooked at 400 degrees so i dont think that realy amounts to anything

you've done some welding....apparently welding/cutting in cold weather can weaken metal even further.

we were discussing welding large metal tanks in class the other day...apparently this company welded on them during a period of below freezing weather...once the heated water was stored in them they failed...water was only 200 degrees. the tanks didn't fail until it was over 80 degrees outside.

it really doesn't take much.

my question is...what if you were to weld and guesset your frame...then bake it at a really high temp and slowly bring it back down.

the molecular structure of the steel would be in many more "blocks" than it would be before that baking.

my real question is...we go to all the trouble of welding gussets onto this frame...and in the process...after welding on them those points are considerably more rigid...but a hard impact will cause it to crack...rather than bend.... right? or am I reading too much into this...and what I'm talking about really is more useful in INDUSTRIAL applications.

**SWIGIN** · 02-02-2009, 09:57 PM

it would be far better to just build a new frame out of .083 chromeoly.....anything else is a band aid

and that tank had pressure in it .....its different but im not even getting into a engenering debate

**The Goat** · 02-02-2009, 10:07 PM

lol, not trying to debate buddy, and I know a couple of tons of water equates a buttload of pressure.

I was just asking about guys who do metal work...have they seen situations where things failed because of the fast heating and cooling...and is all of this welding on frames turning them into ticking time bombs.

A chromoly frame would be ideal...but people don't seem very interested in getting in a group buy.

3k is a bit steep...even for a rash guy like me. lol.

**daniel_250r** · 02-02-2009, 10:12 PM

3k for a 4130 cromo frame?

**SWIGIN** · 02-02-2009, 10:14 PM

well for one thing i dont quench my welds unless im welding sheet metal and im worried about warping it.

on stock frames (basicly sheet metal) i just weld part way around as not to over heat it then go to another spot till the first spot is cooled.

**SWIGIN** · 02-02-2009, 10:15 PM

Originally Posted by daniel_250r

3k for a 4130 cromo frame?

thats a little high but a dude on here had a deal if he got 3 or 4 guys to go in with him they were only $1080...thats a deal

**The Goat** · 02-02-2009, 10:19 PM

that's what was quoted on here the other day. that was with modifications to run the 450 rear...which presented a couple of problems.

it was 1k with the group buy.

**The Goat** · 02-02-2009, 10:20 PM

I'm down for 1K...and I'm down for 1K soon...I can't swing any more than that for 8 or 9 months.

**SWIGIN** · 02-02-2009, 10:24 PM

dont forget the $80 for shipping he said about...hence $1080

**The Goat** · 02-02-2009, 10:44 PM

lol...I was just rounding man...when you're talking a grand, 80 bucks ain't a whole lot.

**Billy Golightly** · 02-02-2009, 11:19 PM

I have seen this happen a bit before. Its typically why when you bend a frame or something you always bend it back cold and not with heat. Because everytime its heated, you spread the molecules further apart (atleast thats how its been described to me). I also try not to weld things in very cold weather for the same reasons you've mentioned. My dad has always preached that to me.

I do not know enough about the heat treating and tempering processes to really give or say anything more then just babble, but I do know that how quickly you make it cool back down, and how quickly and long it stays at a hot temperature has a direct effect on its hardness properties.

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