Arc welding

About: Arc welding is a research topic. Over the lifetime, 25393 publications have been published within this topic receiving 168182 citations.

Monitoring of GMAW Weld Pool From the Reflected Laser Lines for Real-Time Control

Abstract: Controlling the welding process by monitoring the weld pool surface becomes more and more popular in robotic arc welding. In this paper, we propose a monitoring system to infer the P-gas metal arc welding (GMAW) weld pool geometry from the reflected laser lines, which are projected onto the specular weld pool and reflected onto a diffusive plane. The parallel straight lines are distorted according to the shape of the weld pool and thus contain the weld pool's shape information. Accurately computing the equations of the imaged laser lines in the world coordinate system is critical for the subsequent weld pool shape estimation. This paper focuses on accurately segmenting and identifying the reflected laser lines and novel image processing algorithms are proposed to fulfill this specific task. Experimental results verified the effectiveness of the proposed algorithms.

Effect of A-TIG Welding Process on the Weld Attributes of Type 304LN and 316LN Stainless Steels

Abstract: The specific activated flux has been developed for enhancing the penetration performance of TIG welding process for autogenous welding of type 304LN and 316LN stainless steels through systematic study. Initially single-component fluxes were used to study their effect on depth of penetration and tensile properties. Then multi-component activated flux was developed which was found to produce a significant increase in penetration of 10-12 mm in single-pass TIG welding of type 304LN and 316LN stainless steels. The significant improvement in penetration achieved using the activated flux developed in the present work has been attributed to the constriction of the arc and as well as reversal of Marangoni flow in the molten weld pool. The use of activated flux has been found to overcome the variable weld penetration observed in 316LN stainless steel with <50 ppm of sulfur. There was no degradation in the microstructure and mechanical properties of the A-TIG welds compared to that of the welds produced by conventional TIG welding on the contrary the transverse strength properties of the 304LN and 316LN stainless steel welds produced by A-TIG welding exceeded the minimum specified strength values of the base metals. Improvement in toughness values were observed in 316LN stainless steel produced by A-TIG welding due to refinement in the weld microstructure in the region close to the weld center. Thus, activated flux developed in the present work has greater potential for use during the TIG welding of structural components made of type 304LN and 316LN stainless steels.

Review on magnetically controlled arc welding process

Abstract: External magnetic field (EMF) has a strong effect on the welding arc shape, droplet transfer, weld forming, microstructure, and properties of joint metal. This paper defines the types of external magnetic field and reviews the development of magnetically controlled arc welding process, particularly, the effect of external magnetic field parameters on the welding process. It is found that the welding productivity, the weld formation, the ductility, and toughness of welded metal can be improved; and the welding residual stresses, the chemical inhomogeneity, and the welding defects can be reduced. Finally, the development trend is discussed in the later sections of the paper.

Hybrid laser arc welding of X80 and X120 steel grade

Abstract: The aim of the present work was to investigate the possibilities of hybrid laser arc welding regarding reliable production of longitudinal welds of high strength pipe steels X80 and X120 and to evaluate achievable mechanical properties of laser hybrid welds. The study focused on weld toughness examination in low temperature range up to −60°C. Suitable filler materials were identified in the context of this task. It could be shown that metal cored electrodes guaranteed sufficient Charpy impact toughness at low temperature for both investigated materials. Modern arc welding technologies such as modified pulsed spray arc were used to promote deeper penetration of the filler material into the narrow laser welding gap. Edge preparation with a 14 mm deep root face was considered as optimum, because no penetration of the filler material could be detected beyond this depth limit, and therefore, any metallurgical influences on the weld metal properties through the welding wire could be excluded.