Dear and Respected All, I have f 1

[ukmet]

Dear and Respected All,

I have four questions to improve my knowledge:

1) As per ASME Sec IX welder qualification has no restriction on lower thickness than the test coupon thickness. Why could be the reason? Like in some cases isnt it more difficult to weld low thickness than higher due to distortion and higher heat input issues?

2) We have ASME stamped vessel under "U" marking whose MDMT is -41C, thk.10mm. According to ASME Sec.VIII Div 1 UCS 66 vessel is exempted from impact testing if we use normalized plate(it comes below curve D). But we need a impact tested procedure. So I want to know do the test coupon for impact test procedure should also be a normalized plate?

3) I have attached a material test report of a company from which we are thinking to buy the normalized plates. Please review the MTR, the alarming thing is the value of imapct test in Joules it shows? Could the impact test values be so high? If yes than how as nothing such is written in ASME Sec II Part A SA-20.

4) Our previous plates got rejected as they were hot rolled or normalized rolled but not normalized. What actually is the difference between the 2?

Please sort me out

 

[metengr]

1) As per ASME Sec IX welder qualification has no restriction on lower thickness than the test coupon thickness. Why could be the reason? Like in some cases isnt it more difficult to weld low thickness than higher due to distortion and higher heat input issues?

Welder qualification requirements were originally established by the committee to evaluate the ability of the welder to follow a WPS, and demonstrate skill at using one or more welding processes to deposit a sound weld. Nothing more.

2) We have ASME stamped vessel under "U" marking whose MDMT is -41C, thk.10mm. According to ASME Sec.VIII Div 1 UCS 66 vessel is exempted from impact testing if we use normalized plate(it comes below curve D). But we need a impact tested procedure. So I want to know do the test coupon for impact test procedure should also be a normalized plate?

Yes.

3) I have attached a material test report of a company from which we are thinking to buy the normalized plates. Please review the MTR, the alarming thing is the value of imapct test in Joules it shows? Could the impact test values be so high? If yes than how as nothing such is written in ASME Sec II Part A SA-20.

The CVN tests were performed using subsize specimens. The results are what they are unless you want to dispute the results. I have seen high values in SA 516 plate both hot rolled and normalized because of fine grain practice and chemical composition of the plate. This plate is also hot rolled and not normalized.

4) Our previous plates got rejected as they were hot rolled or normalized rolled but not normalized. What actually is the difference between the 2?

Hot rolled means the plates were heated and formed above the recrystallization temperature and eventually cooled in air. No subsequent heat treatment was performed after hot rolling.
Normalization heat treatment is separate and can be performed after hot rolling by reheating the plate until a full austenitization condition is reached and cooling in air from this temperature. The normalization does not necessarily require a separate heat treatment step. However, if the plate normalization is performed immediately after hot forming, the austenitization temperature must be reached upon reheating and verified. Once the austenitization temperature is reached and held until uniform, the plate can be immediately cooled in air.

 

[EdStainless]

Typically when normalizing is done along with the hot rolling it is referred to as 'process normalized'.


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Plymouth Tube

 

[ukmet]

I am so grateful to you for always educating me so much. Its a great honour for me. Sir the first page of this MTR shows normalizing temperature and holding time. Are these two factors enough to establish that the plate is normalized though at the upper right corner it is written Hot rolled plate. Recently we had our ASME re-certification audit in which the ASME team leader rejected the plates just because the marking was "MT" and on MTR it was written "N" nothing else. So he demanded that normalizing temperature and holding time should be given to prove it is normalized.

Please comment

 

[redpicker]

Maybe I'm missing something, but I see nothing on the MTR you posted that refers to a normailzing treatment.
The product is described as HOT ROLLED PLATES.

Under the mechanical properties sections, there is a area for the heat treatment to be identified, but it is blank. This tells me that the mechanical properties listed are for the as-rolled condition. If these plates have been normalized (perhaps shown on another certificate), these mechanical properties would no longer apply, since they are for the as-rolled condiiton.

Or, maybe I'm missing something.

rp

 

[metengr]

ukmet;
You are welcome. Yes, if normalizing temperature and time are reported on the MTR, this is evidence of a normalization treatment for the plates. By the way, some of the ASME team leaders having nothing better to do other than nit pick. I may be doing this as part of my new consulting activity.

 

[ukmet]

redpicker

I could not attach the first page of MTR where it was written about normalizing


metengr

I got it now.