Modelling of Charpy energy in terms of normalisation heat treatment parameters

Abstract

A study has been made of the effect of post-weld normalisation heat treatment parameters on the impact resistance of ¯ash welded AISI type 1330 steel joints. Bars machined from the as welded joints were normalised by annealing at various temperatures for different time intervals, followed by cooling in air. Charpy specimens were machined with their notched section coinciding with the weld plane, and then impact tested at 0°C. The Charpy energy values were modelled in terms of the heat treatment parameters (temperature and time) using appropriate mathematical expressions. Exponential and polynomial formulations were adopted, and the average deviation of the modelled energy values from the experimental data was shown to be less than 10%. The optimum normalisation parameters, which ensure highest impact resistance, were predicted by the proposed models, and are presented and discussed in terms of pertinent microstructural aspects of the heat treated joints.MST/4940