Yield strength variation with temperature

[lax]

anyone can help me out by providing the mathematical relationship between yield strength and temperature

 

[PerennialII]

hi lax ... what material is in question? With respect to room temperature, 'upwards' or 'downwards'?

 

[Astronuc]

Yield strength decreases with increasing temperature, but the relationship depends on the type of material.

 

[radou]

I have a few great diagrams on that topic in my strength of materials book, too bad I don't have a scanner.

 

[FredGarvin]

If you tell us what materials, I am sure one of us would be able to reference a source for what you need.

 

[lax]

Dear all ,
Thank You 4 replying me.
Actually I need Yield Strength Temperature Correction factor in my Calculations for following materials (Alloys of Stell) at various temperatures ranging from 200 Degree Fahrenheit to 800 Degree Farenheit:
1. 9CR-1MO (Chromium- 8-10%)
2. 410-13CR (Chromium- 12.5-13.5%)
3. 925 INCOLOY (Nickel- 42-46%)
4. 718 INCONEL (Nickel- 50-55%)
I mentioned major alloying Element in each alloy.
If You need more information about these alloys , Pl. let me know.
I'll be very greatful if any of you solve my problem.

 

[Astronuc]

The other part of the problem is the residual cold work. Are the materials in question fully annealed or cold-worked, which affects in the initial YS?

 

[FredGarvin]

Inco 718 (page 1):
http://www.specialmetals.com/documents/Inconel%20alloy%20718.pdf

Inco 925 (page 1):
http://www.specialmetals.com/documents/Incoloy%20alloy%20925.pdf

I'm still trying to find something on line for the other two.

 

[lax]

Thank You Fredgarvin for providing the links.
For Incoloy 925, We are able to find the variation of YS with temperature in the form of a curve in the given link.
I know that the variation is non-linear.But Cannot we find out the mathematical Relation for that, which'll be very much helpful to me.
Dear Austronac,
why don't You provide the information I asked for annealed as well as cold worked

 

[FredGarvin]

Do you have access to a program like Excel? Simply plot the points and curve fit them to get the relationship.

 

[lax]

FredGarvin,

What you told is correct but the problem is you need to select the option in which manner (Exponential,logarthmic, polynomial,etc) the variation would be while doing it in Excel.
I feel it would be correct if we know the relationship b/w Yield Strength and temperature.
As per my observation it may be dependent on Youngs Modulus and Poisson's ratio also.Iam not sure of that.Could you please think over it once again?

 

[lax]

Dear all,
I got Some info reg. factors affecting yield stress.
There I found 2 eq.in which how Yield stress is affected by temperature is given.But problem is most of the terms in those eq. are constants, which Iam unable to understand.

You can find this info on
http://en.wikipedia.org/wiki/Yield_(engineering)

Pl. go through it n let me know if you understand it.