Factors Affecting the Notch Toughness of Carbon and Low-Alloy Steel Forgings for Pressure Vessel and Piping Applications

When notch toughness is required in a forging for pressure vessel or piping application, many phases of the manufacturing process are involved. Some significant aspects including the role of the material specification, chemistry balance, mechanical test locations, forging practice and heat treatment are reviewed. A variant of the heat treatment process is described which utilizes quenching from the intercritical temperature range as a means of enhancing notch toughness.