PWHT Stress Relief Calculator

Calculate post-weld heat treatment (PWHT) hold time and temperature for stress relief per ASME PCC-2 and ASME BPVC Section VIII

Input Parameters

Results

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Required Hold Time
hours
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Required Temp Range
°C
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Total PWHT Cycle Time
hours
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Est. Stress Reduction
%
Note: PWHT stress relief reduces residual stresses to prevent SCC and hydrogen cracking, and tempers hard HAZ microstructures. ASME BPVC Sec VIII Div 1 (UCS-56) and PCC-2 Art 5.2 define mandatory PWHT requirements.

Reference

ASME PWHT Requirements: P-No.1 (CS): 595-720°C, 1 hr/25mm (min 1 hr) P-No.4 (Cr-Mo): 680-730°C, 1 hr/25mm P-No.5A (2.25Cr): 680-760°C, 1 hr/25mm Heating rate: ≤220°C/hr × 25/thk(mm) above 300°C Cooling rate: ≤280°C/hr × 25/thk(mm) above 300°C