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Ford Ranger 2
- Thread starter sandman21
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2
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IceStationZebra
Mechanical
Curious why do you want to know?
And I seriously doubt there is any post-assembly heat treating - you would need a very large oven and it would add $$. Even if the frame rails are heated prior to forming, any quick cooling needed to provide any significant hardening would cause semi-random distortion. And from a fatigue standpoint you would want the softer material. I would expect localized work hardening in the corners.
Maybe somebody with some metallurgy experience can weigh in, but I wonder if material with the flammability properties need to make frame rails would take to heat treating very well?
ISZ
And I seriously doubt there is any post-assembly heat treating - you would need a very large oven and it would add $$. Even if the frame rails are heated prior to forming, any quick cooling needed to provide any significant hardening would cause semi-random distortion. And from a fatigue standpoint you would want the softer material. I would expect localized work hardening in the corners.
Maybe somebody with some metallurgy experience can weigh in, but I wonder if material with the flammability properties need to make frame rails would take to heat treating very well?
ISZ
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I am attempting to end an argument that welding to the frame (such as a roll cage or in-filling the c-channel with plate) will remove the heat treatment the frame has received. This makes no sense to me but I wanted to see if I could find individuals who are more knowledgeable in this field.
Certain types of frames are heat treated. Most notably Semis, There is always a label stating that the frame should not be drilled, welded, (and a whole bunch of other things) due to it being a heat treated structural part.
Not a chance that the frame is heat treated post assembly, it would be possible to use heat treated C channel, however from a mass production standpoint its not very likely.
I would hazard a bet that the frame rails of the light duty trucks (ranger, s10 etc...) are made of cold formed HSLA steel, this steel provides high strength after forming while allowing significant elongation and good formability in the as slit, and blanked form. It is also way less expensive than any hardening alloy.
Nick
I love materials science!
Not a chance that the frame is heat treated post assembly, it would be possible to use heat treated C channel, however from a mass production standpoint its not very likely.
I would hazard a bet that the frame rails of the light duty trucks (ranger, s10 etc...) are made of cold formed HSLA steel, this steel provides high strength after forming while allowing significant elongation and good formability in the as slit, and blanked form. It is also way less expensive than any hardening alloy.
Nick
I love materials science!
My friend runs a chassis shop and does a lot of collision work. He had a factory bulletin about newer model frames that were hydro-formed saying they should not be welded to repair, I believe this was on Ford trucks but I don't know if that includes Rangers though.
Wow, this thread is a bit of a mess.
The "frame" of a vehicle is not a single part with a single material and a single heat treatment.
In general, truck frames are simple panels and channels that are stiffness limited and are not improved by increasing the material strength. Thus, they are hot rolled steel with no thermomechanical processing.
There are some rails that may be connected to the front bumper (crash safety critical) that may be hydroformed and have different material and heat treatment.
No thermal cutting nor joining should be done on safety-critical parts without complete knowledge of material, treatments, environment, usage, etc.
Regards,
Cory
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.
The "frame" of a vehicle is not a single part with a single material and a single heat treatment.
In general, truck frames are simple panels and channels that are stiffness limited and are not improved by increasing the material strength. Thus, they are hot rolled steel with no thermomechanical processing.
There are some rails that may be connected to the front bumper (crash safety critical) that may be hydroformed and have different material and heat treatment.
No thermal cutting nor joining should be done on safety-critical parts without complete knowledge of material, treatments, environment, usage, etc.
Regards,
Cory
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.
IceStationZebra
Mechanical
Ice Station Zebra is a movie from 1968 with Rock Hudson and Ernest Borgnine. It is a name that I can easily remember and is rarely taken. 
I concur with NickE on the semi frames. This also applies to at least some medium duty trucks. (I know the Chevy Topkick/GMC Kodiak for certain.) To be on the safe side I would assume that any frame that has all the crossmembers either bolted or riveted in place is heat treated.
While I agree that a "frame" is not a single part, any part that is welded already is highly unlikely to be heat treated as welding will locally re-heat treat the material. Now obviously whomever carries out modifications to a vehicle's frame or suspension parts must realize that a certain amount of risk goes along with such actions. (Just like everything else in life!)
As far as heat treating goes, you could do a Google search and find tons on info. But the 30 second story is that metals are crystalline lattice structures. The actual structure depends on the alloying elements used (carbon, manganese, chromium, vanadium, tungsten, etc.) and the cooling schedule. Different lattice structures have different mechanical properties. While you can't easily change the alloying of a piece of steel, you can reheat it and use a different cooling schedule - a.k.a "heat treating."
The material properties in the weld zone mainly depend on the material types of the two parts being joined, the filler metal, the flux/shielding gas used, and the cooling rate. Assuming the weld is properly sized the weakest area of the joint is usually directly adjacent to the weld - "the heat affected zone". This parent material has been heated by the welding process but relatively rapidly cooled due to the thermal mass of the parent part, often resulting in a more brittle material. (One reason the relatively slow TIG process can turn out higher quality joints is the slower heating/cooling.) Then adding to the problem weld joints are quite often is high stress areas.
ISZ
I concur with NickE on the semi frames. This also applies to at least some medium duty trucks. (I know the Chevy Topkick/GMC Kodiak for certain.) To be on the safe side I would assume that any frame that has all the crossmembers either bolted or riveted in place is heat treated.
While I agree that a "frame" is not a single part, any part that is welded already is highly unlikely to be heat treated as welding will locally re-heat treat the material. Now obviously whomever carries out modifications to a vehicle's frame or suspension parts must realize that a certain amount of risk goes along with such actions. (Just like everything else in life!)
As far as heat treating goes, you could do a Google search and find tons on info. But the 30 second story is that metals are crystalline lattice structures. The actual structure depends on the alloying elements used (carbon, manganese, chromium, vanadium, tungsten, etc.) and the cooling schedule. Different lattice structures have different mechanical properties. While you can't easily change the alloying of a piece of steel, you can reheat it and use a different cooling schedule - a.k.a "heat treating."
The material properties in the weld zone mainly depend on the material types of the two parts being joined, the filler metal, the flux/shielding gas used, and the cooling rate. Assuming the weld is properly sized the weakest area of the joint is usually directly adjacent to the weld - "the heat affected zone". This parent material has been heated by the welding process but relatively rapidly cooled due to the thermal mass of the parent part, often resulting in a more brittle material. (One reason the relatively slow TIG process can turn out higher quality joints is the slower heating/cooling.) Then adding to the problem weld joints are quite often is high stress areas.
ISZ
I'd be the restriction on welding of hydroformed light truck frames is a direct result of the manufacturing process and not the metal used. It's likely still low carbon steel. However Hydroforming (it seems to me) would cold work the entire member, thus if you weld on it you would cause recrystallization and subsequent loss of strength in the HAZ around the weld.
Nick
I love materials science!
Nick
I love materials science!
GregLocock
Automotive
I haven't seen a ranger frame up close, the chances are that each main rail is formed by welding two C sections to form a box, and then each crossmember is welded in. The rails /could/ be hydroformed boxes at some sacrifice in weight.
I'll wear pink for a day if there is any post welding heat treatment.
However, the durability of those welds will have been carefully assessed.
Cheers
Greg Locock
SIG
lease see FAQ731-376 for tips on how to make the best use of Eng-Tips.
I'll wear pink for a day if there is any post welding heat treatment.
However, the durability of those welds will have been carefully assessed.
Cheers
Greg Locock
SIG
lease see FAQ731-376 for tips on how to make the best use of Eng-Tips.
NormPeterson
Structural
Star for that explanation, ISZ. Especially the last paragraph.
BTW, the first association I get from your handle is Alistair MacLean (the books were always better).
Norm
BTW, the first association I get from your handle is Alistair MacLean (the books were always better).
Norm
IceStationZebra
Mechanical
Thanks. I'll have to get the book one of these days!
A few more thoughts came to mind with the roll cage application....
- If you are racing make sure you check any applicable rules. They vary but might require a certified weldor, or they might forbid arc or even wire feed welding. Some lower classes allow bolt-in cages to eliminate mishaps with bad welding/design.
- Also make sure to thoroughly clean the weld areas on the frame as any corrosion or foreign material will contaminate the weld.
ISZ
A few more thoughts came to mind with the roll cage application....
- If you are racing make sure you check any applicable rules. They vary but might require a certified weldor, or they might forbid arc or even wire feed welding. Some lower classes allow bolt-in cages to eliminate mishaps with bad welding/design.
- Also make sure to thoroughly clean the weld areas on the frame as any corrosion or foreign material will contaminate the weld.
ISZ
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