First Report of the Welding Research Committee. A Preliminary Research into the Effect of Heat Treatment of Welds

With such considerations as the releasing of internal stress, the effect on corrodibility, and the practicability of carrying out high-temperature treatments, the present research does not deal. The experiments concern solely the changes in toughness brought about by heat treatment, and they represent a trial set of tests in which a particular high-class electrode was used, the results being intended as a guide for future research.

In the past there has been considerable variability in the results obtained from a normalizing treatment by different experimenters, and as this was considered to be partly due to a difference in manner of cutting out the samples and a difference in the method of carrying out the treatment, the present treatments were all kept under careful control. The upper and lower “runs” were tested separately so that the effect of heat treatment on the coarse metal of the upper run and the fine metal of the lower runs might be subdivided.

Throughout, microscopic examinations were made so that the change in structure might be correlated as far as possible with the change in the shock value. The particular weld metal tested gave very consistent results and the change in Izod value was found largely to follow the change in grain size.