Stout, Robert D.
Associate Professor of Metallurgy, Lehigh University, Bethlehem, Pa
Pages: 12 Published: Jan 1950
The properties of weldments at low temperatures are of interest for a number of reasons. One is the use of welded joints at low temperatures and the need for information as to how they will stand up in service. A second reason for testing weldmentsat low temperatures is that one can thereby simulate conveniently the effect of combined stresses, such as may exist in welded structures in service. It is well known that lowering the temperature of testing will have the same effect on the relation between flow stress and fracture stress in ferritic steels as will increasing the rate of loading or increasing the severity of constraint in the specimen. The result of any of these is to lower the ductility and increase the tendency of the steel to fail in a brittle fashion. The discussion here will be limited to a brief survey of past work and some experimental results obtained at Lehigh University. It should be stated first that the effects of low temperature observed in unwelded steels can be expected to occur in weldments as well. The effect of welding is usually to intensify these effects. Except in mild steels, the welding operation is apt to be accompanied by an impairment of ductility and notch resistance in the steel. Thus, if the steel to be welded is of poor quality and properties, welding cannot be expected to improve it, but rather may introduce additional difficulties. In order to reveal the low-temperature properties of steel, suitable testing methods are required, as the other papers of this Symposium have indicated.
Paper ID: STP46235S