Butt welding

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

Method for butt welding of clad pipe

Abstract: PURPOSE: To improve the welding quality of a pipe joint part by the butt welding of clad pipes of double layer structure (inner layer: high nickel stainless steel, outer layer: carbon steel) to be used for line pipes for the sour oil field. CONSTITUTION: In the welding where clad pipes 10 having the concentric laminated structure of an inner layer 11 consisting of high Ni stainless steel and an outer layer 12 consisting of carbon steel are butted to each other, and the welded metal layer W a consisting of high Ni stainless steel, the buffer layer W b and the outer layer welded metal layer W c consisting of carbon steel are laminated in the groove G, the buffer layer W b is formed of pure nickel material. COPYRIGHT: (C)1996,JPO

Butt-welding device

Abstract: A butt welding device wherein the trailing edge of a first or preceding strip and the leading edge of a second or succeeding strip are clamped in position, simultaneously cut off, and joined together by flash butt welding and thereafter the flash and upset are removed by machining.

Defects and process tolerances in welding of thick plates

Abstract: Laser welding and laser-GMA-hybrid welding using 8 kW, 20 kW and 30 kW fiber lasers was investigated. Steel plates from low alloyed steel (e.g. pipeline steel X65) having a thickness of 16 mm up to 28 mm were joined under various conditions. Single layer laser-GMA-hybrid welding as well as multi layer hybrid welding were investigated for different seam preparation types. Butt welds and different types of Y-welds have been tested. The air gap and the edge misalignment have been varied intentionally to investigate the process window as it is also intended to use the process in rough environment. Different types of phenomena which reduced the efficiency of the process (measured by the welding depth) were detected. In laser welding a significant influence of the focal length was seen, in which a short focal length reduced the penetration depth strongly. Multi layer hybrid welding resulted in pore formation while single layer hybrid welding showed reasonable good results.Laser welding and laser-GMA-hybrid welding using 8 kW, 20 kW and 30 kW fiber lasers was investigated. Steel plates from low alloyed steel (e.g. pipeline steel X65) having a thickness of 16 mm up to 28 mm were joined under various conditions. Single layer laser-GMA-hybrid welding as well as multi layer hybrid welding were investigated for different seam preparation types. Butt welds and different types of Y-welds have been tested. The air gap and the edge misalignment have been varied intentionally to investigate the process window as it is also intended to use the process in rough environment. Different types of phenomena which reduced the efficiency of the process (measured by the welding depth) were detected. In laser welding a significant influence of the focal length was seen, in which a short focal length reduced the penetration depth strongly. Multi layer hybrid welding resulted in pore formation while single layer hybrid welding showed reasonable good results.

Effect of Size of Butt Weld Repairs on Weld Overlay Residual Stresses

Abstract: Weld overlays have been used to provide repair and mitigation to stress corrosion cracking (SCC) susceptible butt welds in nuclear power plant piping. Among the several advantages associated with weld overlays are the beneficial compressive residual stresses that are developed in the inner portion of the component after application of the overlay. These compressive stresses can provide significant mitigation against SCC in these welds. To determine the residual stresses resulting from the weld overlay process in analytical modeling, a weld repair during original fabrication of the butt weld is typically assumed before application of the weld overlay. If the fabrication records are available, the details of the weld repair can be simulated in the analysis. However, in most cases, the weld records are not easily accessible and in instances where they are available, the quality and completeness of the information are questionable. As such, various conservative assumptions are made on the extent of the weld repair to be simulated in the analytical modeling. In this paper, the residual stress results of an axisymmetric finite element simulation of a bimetallic weld subjected to an inside surface weld repair followed by a weld overlay repair are presented. Three through-wall weld repair sizes (25%, 50% and 75% of the wall thickness without the overlay) assumed to be full 360° around the circumference were considered in the study. The results indicate that for all three weld repair cases, the inside of the configuration is very tensile after the weld repair indicating that regardless of the size of the weld repair, SCC is a possibility. The post weld repair stress distribution of the 50% and the 75% repair cases are similar indicating that an assumed 50% repair is fairly representative of repairs that can be assumed for analysis purposes. The application of the overlay resulted in favorable compressive stresses on the inside portion of the configuration for all the three weld repair cases indicating that regardless of the size of the initial weld repair, the application of the weld overlay provides mitigation against SCC.Copyright © 2007 by ASME