Dish end heat treatment

[hyl]

Hello members
we have conflict with the fabricater of the dish end .about heat treatment .The dish is fabricated by cold forming according to (UCS-79) detail (d).the dish must be heat treated if the extreme fiber elongation is more than 5%.the fabricater give us calculation according to the attach .we are indoubt about this calculation please.about the use of Rf and Ro in the equation is correct .please advice us .

also in (UCS-79) detail (3) the material thickness is more than 16mm it must be heat treated .what the advice about that please .

what is the maximum allowable limt hardness in carbon steel A515 GR60 .

THANKX IN ADVANCE

jamil a alshahed nama
hartha power station

 

[metengr]

hyl;
I believe that R_f and R_o are well defined in UCS-79 based on the supplied formulas. In this same paragraph, for P-No 1, Groups 1 and 2 base materials, you can go up to 40% fiber elongation provided none of the conditions in (1) through (5) exist. If the thickness in the part exceeds 5/8" or 16mm, a subcritical heat treatment must be performed if the fiber elongation is more than 5% based on (3).