Abstract
This paper describes a new measuring method of residual stress distributions in welds qualitatively using an optical interference method. The principle of this method is based on measuring by an interference fringe (surface relief), induced on a specimen when deformed and/or treated by stress-relief annealing. The method may be characterized mainly in the following measurements:
1) Only by lapping a surface of a specimen, the location of stress concentration and the range of plastic deformation can be easily known.
2) Combined with cutting and annealing, unique patterns of surface relief are revealed respectively due to stress release in z-, xy-, and xyz- directions.
3) This method can be also utilized under subzero temperature, and furthermore, even at higher temperature by use of a laser.
