Is there a ASTM method for estimating grain size in welds?
3

Question

Is there a ASTM method for estimating grain size in welds?

EngineerDave (Bioengineer)

(OP)

30 Mar 04 13:28

I know this is a dumb question, but I was asked to provide a grain size of the weld material (not the base metal or heat affected zone). Since the weld material is very irregular can one truly provide a grain size of the weld?

Thanks in advance for any help. I know I didn't provide alot of details on the weld itself, it's mainly because I don't have much info on it. But it is weld filler material and the microstructure is very irregular. Not sure I can even provide a true grain estimate, but maybe some size information.

metengr (Materials) · Answer 1 · 2004-03-30 13:41:37

EngineerDave;
From the publications I have seen, the ASTM method E112 (intercept or other) for determination of grain size can be applied to wrought or cast product forms. Welds would be considered a cast product form.

unclesyd (Materials) · Answer 2 · 2004-03-30 14:12:14

I never seen a grain size on as welded product due it being mostly dendritic.

metengr (Materials) · Answer 3 · 2004-03-30 14:36:00

unclesyd;
Yes, I have never seen welds have a grain size identified for components we purchase. On the other hand, I don't see why you couldn't attempt to determine an average grain size using the intercept method where you would have a columnar grain structure instead of all dendrites.

As a side note, I did see a technical paper where the weld grain size was determined using the intercept method, which caught my attention. It must have been an academic exercise.

EngineerDave (Bioengineer) · Answer 4 · 2004-03-30 15:37:15

Thanks guys. The dendritic structure and absence of clear boundaries are exactly my problem. I just finished explaining that to my customer.

I'll let you know if we give it a try. I would use my image analysis software and an intercept method.

TVP (Materials) · Answer 5 · 2004-03-30 16:41:38

Dave,

FYI, there are a number of ASTM methods that discuss grain size including the following:

ASTM E 1382 Standard Test Methods for Determining Average Grain Size Using Semiautomatic and Automatic Image Analysis

ASTM E 930 Standard Test Methods for Estimating the Largest Grain Observed in Metallographic Section (ALA Grain Size)

ASTM E 1269 Standard Practice for Assessing the Degree of Banding or Orientation of Microstructures

You may want to consider more than just an intercept technique, for the reasons already stated.

sayee1 (Materials) · Answer 6 · 2004-03-30 22:33:04

My only contribution to this post were the stars!!!!

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Is there a ASTM method for estimating grain size in welds?
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