Butt welding

About: Butt welding is a research topic. Over the lifetime, 7153 publications have been published within this topic receiving 44467 citations.

Welding method for the connection of a component to a workpiece, and a device for carrying out the method

Abstract: In a welding method for the connection of a component (6) to a workpiece (7) by means of an arc between the component end and a welding point on the workpiece (7), the arc voltage is set and is monitored continuously during the welding process. The component lift is in each case automatically adjusted accordingly.

Fatigue strength prediction of ultra high strength steel butt-welded joints

Abstract: First, fatigue tests were performed on butt-welded joints made of novel direct quenched ultra high strength steel with high quality welds. Two different welding processes were used: MAG and Pulsed MAG. The weld profiles, misalignments and residual stresses were measured, and the material properties of the heat-affected zone were determined. Fatigue tests were carried out with constant amplitude tensile loading both for joints in as-welded condition and for joints after ultrasonic peening treatment. Finally, in fatigue strength predictions, the crack initiation phase was estimated using the procedures described by Lawrence et al. [Lawrence F V, Ho N J and Mazumdar P K (1981) Predicting the fatigue resistance of welds. Annu. Rev. Mater. Sci, 11, 401–425]. The propagation phase was simply estimated using S–N curves for normal quality butt welds, which may contain pre-existing cracks or crack-like defects eliminating the crack initiation stage.

Practical welding techniques to minimize distortion in lightweight ship structures

Abstract: The trend in both military and commercial shipbuilding is the increased use of thin steel to reduce weight and improve performance. Complex panel structures have thickness transitions for weight and structural optimization with multiple inserts ranging from 5 to 45 mm. Welding practices developed for thicker plate can result in significant out-of-plane distortion when applied to thin-plate structures. Buckling distortion of complex lightweight panels has resulted in a significant negative effect on manufacturing cost and production throughput, limiting the shipbuilders' ability to produce innovative ship designs. High fitting and welding costs are the consequence of this large welding distortion. This problem is exacerbated as the fairness requirements are tightened. New methods are needed to control distortion when welding thinner materials. To tackle the distortion problems, in 2002 Northrop Grumman Ship Systems initiated a multiyear program to develop distortion-control technology for complex panels. This paper reports the results of a study to develop "best practices" for welding of lightweight structures. Control of welding distortion for thin structures requires control of each welding operation from butt welding of plates through to unit assembly. A general philosophy was applied to minimize welding heat input while maximizing restraint during unit construction. To achieve this, the following techniques were evaluated: increasing restraint during each welding operation, improving fitting practice, weld sequencing, and minimizing welding heat input. Additionally, an active distortion mitigation approach, known as transient thermal tensioning, was investigated for reduction of buckling distortion during thin-panel longitudinal stiffener welding. A series of tests were performed to evaluate various distortion control approaches and to optimize production processes. The culmination of the project will involve demonstrating best practices in the production of thin-steel structures. A plan is also being developed for implementing the most advantageous approaches into production.

Boom and dipper stick construction

Abstract: A boom and dipper stick construction for mobile excavators and an improved method of manufacturing the same. The boom and dipper stick are fabricated from side plates that are butt welded together with respect to various hinge point locations to eliminate the necessity of doubler plates on the sides of the structures. The butt welds are located at non-critical areas to provide for even stress flow and ease of manufacture. A method of welding together the side plates of the boom and dipper stick construction in an end to end abutting relationship in a manner which attains a complete weld penetration over the entire length of the joint.

Hybrid laser and resistance welding system and method

Abstract: An improved fusion welding system having a heating unit and welding device is adapted for increasing the efficiency of welding a plurality of workpieces. The system preferably presents a single-sided process, and includes first and second electrode wheels operable to heat a portion of the workpieces to a minimum temperature, and a translatable laser cooperatively configured to form a continuous weld within the heated portion. The preferred system provides the advantages of laser welding, such as precision, while enabling weld production at lower laser power outputs or faster welding speeds than conventional laser welding systems.