Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

  • Congratulations waross on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Grain size variance

Status
Not open for further replies.

mking0919

Mechanical
Apr 4, 2022
2
US
I am having an issue that is beyond my limited knowledge of metallurgy. My company makes extruded fin tubing for use in heat exchangers. I was given a sample of a raw copper tube that was too soft for our operators to run it. It was being crushed as it passed through the machine. My boss wanted me to verify that the material was nonconforming and there for rejectable. When I analyzed the sample I expected to see grains that were larger than what was specified in the purchase order. What I found however were clusters of small and medium sized grains surrounding larger ones. I was wondering if anyone might know what would cause this. I have never had this issue before and I'm stumped.
 
Replies continue below

Recommended for you

Which copper alloy?
Sounds like partial recrystallization after cold work.


= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, consulting work welcomed
 
An old Copper Development document shows C 122 tubing can be ordered to ASTM B- 68 ,75, 88, 111, 280, 306, 359, 360, 395, 447, or 543. I expect some of the ASTM specs have been discontinued but there are still many options from annealed to hard drawn. Tubing yield strength can be from 10,000 to 50,000 psi. What exactly was ordered?
 
Status
Not open for further replies.

Part and Inventory Search

Sponsor

Back
Top