Super Duplex

[blckwtr]

If you have a piece of material with an assigned length, then heat it and cool it again. Does the material shrink relative to the initial length?

 

[owenmaterials]

It depends on whether the material has residue stress in it to start with. If the residue stress is negligible, it should not shrink -- my personal opinion.

 

[metengr]

If you have a piece of material with an assigned length, then heat it and cool it again. Does the material shrink relative to the initial length?

Not enough information to answer your question. What is the material and what temperature range?

 

[davefitz]

If the component as restrained from growth during the heating cycle, and the Ea*DT exceeded yield, then it would yield in compression- the following cooldown process may leave a reduction in length , proportional to the plastic yielding .

 

[EdStainless]

If: little residual stress, no restraint, and no chance of any phase changes; then there will be no length change.

That said, there are a bunch of ways to get length change on thermal cycling. How much are you talking? What product form?

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Plymouth Tube

 

[blckwtr]

ok, this was actually ment as a general question, but here we go;

We have had some problems with a pipe, size 355,6mm, thickness 35,7mm after machining. This also has threads in one end. After machining, a bracket is welded on the threaded side.

The problem now, is that the end lid (threaded part) does not fit after the welding process.

One of the welders said that super duplex shrinks when it is heat treated, a statement I find very general.

 

[metengr]

The above dimensional changes are from residual stresses as a result of the heat input from welding.