are all seamless pipes made under ASTM A106GrB NACE compliant?

[31903190]

Please can somebody let me know if a pipe produced under ASTM A106 GrB is NACE compliant? i see NACE wants materials to have less then 1% nickel value whereas ASTM allows 0.4% and the max tensile strength is somewhere around 510MPA which corresponds to hardness well below HRC22 as allowed by NACE..Can somebody confirm this?

 

[SJones]

It's also about hardness and possibly about HIC testing. In general, you could get lucky with off the shelf material, but the only guarantee will be to specifically order it to be compliant. The ASTM nickel content requirement is a MAXIMUM value, not a minimum.

Steve Jones
Materials & Corrosion Engineer

http://www.linkedin.com/pub/8/83b/b04

 

[31903190]

Thank you for the comment, yes you are right ASTM percentage is a maximum of 0.4% whereas NACE is 1% i think this aspect is well covered.

As for hardness i saw a number of MTR's for A106GrB material and all show tensile strength of about 490MPA with corresponds to a hardness level well below 100HRB of 22HRC.

Any comments on this?

 

[31903190]

the standard involved is only NACE MR 0175

 

[SJones]

Hardness has to be determined by measurement rather than by inference.

Steve Jones
Materials & Corrosion Engineer

http://www.linkedin.com/pub/8/83b/b04

 

[stanweld]

You will have no problem neeting the Ni and hardness requirements with A106 B purchased from stockists; however,in welding, the HAZ may be unable to meet the hardness requirement without PWHT due to higher carbon equivalents than may be evident on the MTR. Manufacturers are adding micro-alloying elements without disclosure in the current "one-size-fits-all" steel making philosophy. We have seen numerous heats of A106 made to fine grain melting with additions of Nb and V and/or Al.

So, Buyer beware!

 

[31903190]

What if the pipes are seamless?

 

[SJones]

You will still have to weld them together, unless they are for fence posts or flower pots!!

Steve Jones
Materials & Corrosion Engineer

http://www.linkedin.com/pub/8/83b/b04