1987 Volume 5 Issue 1 Pages 87-93
The method for predicting the toughness of multi-pass weld HAZ by simple thermal cycle simulation was investigated on the basis of the distribution of toughness which had been discussed in the previous report.
The main results obtained were as follows.
(1) It was confirmed that the toughness of single-pass weld HAZ could be predicted by single thermal cycle simulated specimen with the same cooling rate. It was difficult to predict the toughness of multi-pass weld HAZ by single thermal cycle simulated specimens.
(2) Double thermal cycle simulation test (Peak temperature: 1350°C-650°C) was effective for the prediction of the toughness of multi-pass weld HAZ. That is, tempering thermal cycle (Peak temperature: 650°C) was essential for the simulation test.
(3) Average toughness calculated by using value of the toughness and area fraction of each microstructure distributed in HAZ almost agreed with the measured toughness of multi-pass weld HAZ.
