Showing papers in "Welding Journal in 1974"

Assessing the significance of flaws in welds subject to fatigue

Abstract: The substitution of fracture mechanics crack propagation data for simple S-N curves provides additional data on welds defects, other than applied stress and the influence of geometry. It allows the fatigue process to be entered (variation in initial flaw size) and left (variation in failure criterion) at will and variations in geometry and crack share to be taken into account. The value of the method has been confirmed by accurately predicting the fatigue behavior of fillet welds containing flaws on the basis of the generalized stress parameter.

Resistance welding parameter profile for spot welding aluminum

Abstract: As tip force is increased, there is a larger tolerance in the variation of the other welding parameters, i.e., current and weld duration where good weld quality is obtained. Longer weld current duration reduces the tendency to have cracks appearing in the sheet under the electrodes. There is a near linear correlation between welding current and shear strength which is independent of the number of weld cycles and tip force used.

Fracture toughness study of a grade 300 maraging steel weld joint

Abstract: The plane strain fracture toughness (K sub Ic) of a gas tungsten-arc (GTA) welded joint prepared from 10 mm ().39 in.) thick, grade 300, maraging steel was determined. All critical K sub I values less than about 270 kp mm to the -3/2 (76 ksi in. to the 1/2) satisfied ASTM validity criteria for K sub Ic; these included determinations for all microstructures except one that was characterized by a very high stable austenite content. The effect of microstructural and property variations characteristic of the HAZ (Heat Affected Zone) on the determination of K sub Ic was studied using "weld simulation" specimens thermally treated in a Smit weld simulator. Results were correlated with those obtained from actual welds on the basis of equivalent microstructures, mechanical properties, and thermal treatments. From this study, a tendency towards embrittlement due to short time exposure at 750 C was detected. It was also noted that K sub Ic appeared to be independent of grain size.

Application of a smoke extracting system for continuous electrode arc welding

Abstract: Development of a smoke extracting system for gas metal-arc and flux cored arc welding has been achieved, and a thorough study of the effectiveness of this smoke exhaust system has been made. This article presents the requirements of a smoke exhaust system and gives a description of such a system and its various components. A thorough discussion of two series of test programs is presented, and as a result, it is concluded that the smoke exhaust system meets the requirements presented.

Electroslag welding speeds shipbuilding

Abstract: A step by step description of electroslag welding and the mechanical equipment employed in the process Included are tables showing the time saved in welding side shell butt joint and longitudinal stiffeners broken down by the time saving achieved in each step of the process

Corrosion prevention with thermal sprayed zinc and aluminum coatings

Abstract: In a program conceived in July 1950, the American Welding Society Committee on Thermal Spraying began an extensive study of the corrosion protection afforded by wire flame sprayed zinc and aluminum coatings applied to low carbon steel. Over four thousand test panels were prepared for distribution to eight strategic test sites across the United States. Panels were exposed to sea water at mean tide and below tide levels at two different locations, and at six other locations, panels were exposed to atmospheric conditions including industrial, salt air and salt spray environments. The report presented here gives a brief summary of the study including, 1) methods of preparing the test panels for coating, 2) the various thicknesses in which the coatings were applied, 3) the composition of the sealers and their application where used, 4) the location of the test sites, and 5) the conclusions reached after inspection of the panels. /Author/