Luders band

[kanwer78]

We are testing large number of tensile specimen from a weld region.

Some specimen show luders band phenomena during tensile tests in this case what value for yield strength: upper, lower or the conventional 0.2% should be taken and why?

I was recommended to take the upper, but then in a series of tests, few specimens show an almost horizontal line for yield strength and in this case determining the upper yield strength is very difficult and I would prefer a standard 0.2% for all, will I be wrong in doing so?

I thank you in advance for replies,

Smiles,
Kanwer

 

[swall]

You are correct to ask for the .2% offset yield strength to be used. It was developed exactly for the type of situation you are encountering.

 

[kanwer78]

@swall...

Thanks for your reply, i too think it should be 0.2% for all..

Best Wishes
Kanwer