Effect of Simulated Post-Weld Heat Treatment on the Mechanical Properties and Microstructure of P-No. 1 Carbon Steels

The effect of simulated post-weld heat treatment (PWHT) on the mechanical properties and microstructure of P-No. 1 materials was investigated and the suitability of the exemption requirements of simulated PWHT as specified in ASME Section III Division 1 Subsection NX-2211 was evaluated. SA-516 Gr. 60 and 70 carbon steel plates and SA-106 Gr. B carbon steel pipe were employed, and the materials were subjected to the simulated PWHT with holding temperatures of 610, 650, 690, and 730 °C for 8 hours. Both the tensile strength and lateral expansion of the materials tested in this study showed a tendency to decrease with increasing holding temperature of the simulated PWHT. In some cases, the materials after the simulated PWHT cannot satisfy those mechanical requirements.