Welding Metallurgy of Structural Steels

Abstract

composition requirements for improved cold cracking susceptibility and HAZ toughness, along with the importance of low CE to both properties. TMCP operating mechanisms are then described together with conditions for optimizing their effects on the weldability of structural steels with lowtemperature toughness consistent with Arctic marine environments, tensile strengths > 500 Mpa, and thicknesses of 50 to 100 mm. Recent results at NKK with 63-mm plates are shown in Table I. The stable, accurate control required for producing TMCP steels can be adequately met by present levels of technology, but drawbacks of the process may include a heavy penalty in rolling efficiency. In his paper "A Viewpoint on the Weldability of Modern Structural Steels," P.R. Kirkwood of the British Gas Corporation discussed the controversy which has led to the belief that modern structural steels, particularly the lower sulfur steels, are more difficult to weld than their counterparts of the early 70's. Extensive investigations at British Gas did not appear to support the contention that the newer steels are more difficult to weld, but the inquiry did suggest that the British Standard weldability prediction method becomes increasingly inCritical CTOD Value at woC (mm)***