maximum ultimate tensile strenght for A106 gr B

[engr2GW]

Hi,

I was tensile testing welded sample of A 106 gr B, and the guage is reading an ultimate tensile streght of 87 to 90 ksi, in the spec, the minimum yield is 35 and the minimum tensile is 60 ksi, is the 87 ot 90 too high, is there a guide as to what the max should be or a range. The electrodes are E6010 root and hot pass and and 7010 cap for a 2" A106 B stick welding.

Thank you.

 

[metengr]

Are you sure you understand how to tensile test weld coupon specimens? There is no direct gage for Ksi. You have a maximum load that you read directly and using the original cross sectional area of the coupon you calculate UTS.

Check your testing procedure and data.

 

[engr2GW]

Thanks metengr,
but I know how to tensile test, the gage reads the pressure or the load which you convert UTS by converting to ultimate load and then to UTS by deviding by the speciment area.

I was just wondering if the value makes sense, it seems too high for me which makes me think the gage is faulty.

 

[metengr]

Yes, your UTS seems higher than what I would expect. Check the calibration of the machine.

 

[Eddycurrentguy]

The Material Test Report (MTR) should indicate the actual mechanical properties of the test plate, based upon product heat. You can compare the MTR results to see if the test value is accurate. However, 87-90k seems too high for both the material and weld electrodes used for the test.

I'm also assuming that the failure occured in the base metal? Did you get elongation values? Typical for grade B is 24%-30%, depending on specimen area

 

[engr2GW]

Yes the failure did occur in the base metal. From what I see in the MTR, the 8" has a tensile of 70.3k and the 2" has a tensile of 82k, it doesn't say anything about max. Elongation from the MTR is 45% and 32% respectively

 

[blacksmith37]

A106 B is a minimal smls pipe spec : occasionally higher grades are substituted for limited quantities. As long as your filler metal exceeds the actual pipe strength there should not be a problem. Once saw this situation and the weld metal did not match the high strength pipe (supplied to a low grade spec ), result was ductile overload failures in the weld metal.

 

[Eddycurrentguy]

Could also be a dual grade material.

In any case, the results you got appear to be reasonable as compared to the MTR's. The fact that the failure occured in the base metal and not the weld implies that the welding procedure [and welders] are good as well.

Looks like you may have gotten a material with mechanical properties similar to 516-70 for the price of Grade B.

 

[stanweld]

E7010-A1 can readily achieve 90 ksi tensile strength. While the strength of the A-106 B is abnormally high, it is certainly a possibility depending on chemistry. What was the carbon equivalent? Also some manufactures produce pipe with somewhat high residual Cr, Ni & Mo contents.