ASTM A106 Gr.B vs A333 Gr.6 Stress Curves

[Surveyor82]

I have a question about stress curves.

After doing some research I've found elaborate curves of A106 Gr.B in the API 530 about the rupture stresses but for the life of me, I can't find any data about A333 Gr.6. I don't think I can assume equivalence between the two since A333 Gr.6 is for preferred for low temperature service.

The problem is this: We have materials from both specs, only the first was required yet both are delivered. I want to know if A333 Gr.6 is capable of performing at elevated temperatures (> 400°C).

My preference is 'NO', but... I need sound information that it can or can't be used.

Any help would be amazing! Thanks in advance!

 

[metengr]

Why don't you review ASME Section II, Part D and compare allowable stress values to determine your application? The information is all there regarding service temperature limits and stress values for design.

 

[Surveyor82]

Thanks metengr for pointing me to Section II, Part D. My general knowledge of the ASME code is under construction

I've searched for A333 Gr.6 and found that Table 2A gives the service limit at 371°C. I've found additional information from other codes (Dutch Rules for Pressure Vessels) that restrict the services up to 350°C. Which is the same for A106 Grade B (slightly different in DRPV).

Thanks again!!!!

 

[weldstan]

As temperature increases above 400C, creep strength of A-333 6 will decrease relative to A-106 B because of its fine grain relative to the coarse grain of A-106. Additionally, the fine grain A-333 6 will be subject to an accelerated tendency to graphitization relative to A-106B.

 

[david339933]

You can get duel certified material: SA-333Gr.6/SA-106B

 

[XL83NL]

Is the delivered material dual certified to what david339933 mentioned? If so, you can use the (mechanical) properties of the 'stronger' (or better, if you like) material. It's a parallel with 316/316L.

With DRPV, do you mean RToD? Please note that the chemical composition of A106-B may be different to the Dutch equivalent, hence not hold the same properties.