1976 Volume 45 Issue 4 Pages 309-315
Relating to cold cracking in steel welds, restraint stresses and strains are studied theoretically for the slit weld, in which a slit is made in an infinitely large plate and welding is done into the slit. Restraint of weld will be higher at the ends than at the middle part of the slit. Assumptions used in the analysis are that 1) welding heat is given instantaneously along the length of a slit and 2) throat thickness of weld is rather small as compared with the plate thickness. These assumptions are enable us to make elastic analysis concerning stress-strain in the plate even when general yielding occurs in the weld metal. According to a model considered for obtaining the restraint severity in the weld metal along a slit, restraint deformations in the weld are given by the sum of the elastic movement of the slit edges at elevated temper atures and the contraction of weld metal. Plastic part of the restraint deformations will be a measure of restraint severity in slit weld. It is obtained along a slit as functions of variables such as length of slit, thickness of plate, weld heat input, yield strength of the material etc. General yielding in the wed metall occurs over a certain length near the ends of a slit. The restraint deformation or restraint strain become maximum at a location apart the value of critical plate thickness, or 15-20 mm in shielded-metal-arc-welinbg of steels, from the ends of a slit. Examples of them are calculated for steel welds.