stress relieving of dished ends

[pdprao]

WE NEED TO FABRICATE A TORISPHERICAL DISHED END OF 4200MM DIA WITH KNUCKLE RADIOUS OF 420MM AND CROWN RADIUS OF 4200MM. MATERIALS TO ASTM A516 GR 70, THICKNESS OF PLATE 16MM , MINIMUM ACCEPTABLE THICKNESS AT KNUCKLE AREA 12MM MINIMUM. IMPACT REQUIREMENTS ARE SPECIFIED FOR MATERIALS.

WHETHER THIS WELDMENT NEEDS STRESS RELIVING AS PER ASME SECTION VIII? HOW DO U ARRIVE AT MAXIMUM FIBER ELONGATION?

 

[arto]

Look in UCS-79

 

[codeeng]

For heads you need to assume worst case i.e. the smallest radius and the thickest plate, thus Rf = 440 + (12/2) and t = 16.
75t/Rf = 2.7% < 5% therfore no heat treatment required.