Researches on Welding Stress (Report 1)

On the generation process of welding Strains

Abstract

Although stresses exist in welded specimen both during and after welding, only those remai. ning after specimen has conpletely cooled have much discussed.
As a preliminary experiment for investigation on the generation mechanism of residual stress by welding, Authors inquired into process of arise of welding strain in this experiment, and have taken the following results.
Transverse strain indicates expansion in high temperature above starting temperature of Ar' transformation, but it changes to contraction when temperature of deposited metal falls below Ar' point. As a whole, remarkable amount of contraction is produced by the time deposited metal cools to room temperature. The state of these contraction agreed to result analysed by heat conduction theory (see Fig. 8)
Angular distortion is mostly produced in high temperature range above Ar' transformation.