BACKGROUND INFORMATION:

ASME VIII Div 1; Part UHA; Formed head; Material 304 L: Hot formed at 900 °C.

QUESTION:

a) UHA 44, speaks only about "...cold formed...". Is UHA 44 applicable if the the head is hot formed?

b) What about the hot formed head in UHA part?

Thank you very much for your cooperation.

Sincerely

Bologna. Italy June 25, 2006 Max Morassi

This hot formed head (at 900 oC) requires impact testing as per UHA-51(c)(1). UHA-44 is not applicable.

Any one have differnet opinion?

Surachai

Surachai
900C is not between 600C and 900C. If it was 899C- UHA-51(c)(1) would be applicable.

Konrad

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Konrad Anikiel

Dear Max, I understand your concern is about the requirement of solution treatment per UHA-44.
Please note that Grade 304L is not included in Table UHA-44 therefore solution tratment after fabrication is never required.

For other grades included in Table UHA-44:
Par. UHA-44 applies to material cold formed only, therefore, APPARENTLY, it does not apply for forming temperature of 900 °C.

BUT which temperature is the borderline between cold and hot forming?

Code gives the answer (in my opinion)
Read UHA-44(a)(1)(a) the finishing-forming temperature is below the minimum heat-treating temperature given in table UHA-44. Therefore it is understood that UHA-44 considers cold forming all forming at a temperature below 1040 °C (1090 for 348H).

A hair in the egg is the discussion whether 900 °C is between 600 and 900: in my opinion yes, it is. Therefore impact testing requirement per UHA-51(c)(1) does not apply.

Mauro,
The conclusion is that die-stamping at 900C is thermal treatment per UHA-51(c)(1), but is still cold forming per UHA-44. If I wasn't an engineer, I could believe it's right

Konrad

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Konrad Anikiel