Reduction in Carbon Question

[fefeed]

I have a MTR for 3/4" thick A516 Gr 60N. According to the Astm for each reducion of 0.01% point below the specified max for carbon an increase of 0.06% point above the specified max for manganese is permitted. The astm says that the carbon max for over 1/2" is 0.23% and the Manganese max for over 1/2" is 1.20. My MTR is showing a carbon reading of .20 and a manganese reading of 1.41. The way it looks to me is that I should have manganese max of 1.38? Am I correct. This is not how it was explained to my by another eng at work. He states that it is the Manganese that is related to the carbon content not the other way around. And that those readings are acceptable.

 

[mrfailure]

You have correctly interpreted the spec. I do not quite get your colleague's explanation, but the material does not conform the A516 compositional requirements and should be rejected.

Aaron Tanzer

http://www.lehightesting.com

 

[fefeed]

Thanks mrfailure

He told me to take .21 which is the diffenerce in extra Mn and divide it by 6 add that to the C content and because that was not more than the allowable C content it was good material. He's ASTM certified PE etc but I just wanted to be sure.

 

[redpicker]

Let's see.

0.21/6= 0.035
0.20 + 0.035 = 0.235

0.235 > 0.23
material is not acceptable.

I am not sure I follow.


I have always done it the way you did, that is,
0.23 - 0.20 = 0.03
0.03 * 0.06 = 0.18
1.20 + 0.18 = 1.38 <== This is the max. allowable Mn for 0.20% C

Either way will work, if I understand it, I just don't see how he can say that 0.235 is less than 0.23.


rp

 

[mrfailure]

Just because one has a PE does not mean they can do basic algebra...

Aaron Tanzer

http://www.lehightesting.com

 

[fefeed]

Thanks for the confirmation redpicker

@mrfailure I'm learning that more and more each day