Pavel Layus

Advanced submerged arc welding processes for Arctic structures and ice-going vessels

The Arctic region is expected to play an extremely prominent role in the future of the oil and gas industry as growing demand for natural resources leads to greater exploitation of a region that holds about 25% of the world’s oil and gas reserves. It has become clear that ensuring the necessary reliability of Arctic industrial structures is highly dependent on the welding processes used and the materials employed. The main challenge for welding in Arctic conditions is prevention of the formation of brittle fractures in the weld and base material. One mitigating solution to obtain sufficiently low-transition temperatures of the weld is use of a suitable welding process with properly selected parameters. This work provides a comprehensive review with experimental study of modified submerged arc welding processes used for Arctic applications, such as narrow gap welding, multi-wire welding, and welding with metal powder additions. Case studies covered in this article describe welding of Arctic steels such as X70 12.7-mm plate by multi-wire welding technique. Advanced submerged arc welding processes are compared in terms of deposition rate and welding process operational parameters, and the advantages and disadvantages of each process with respect to low-temperature environment applications are listed. This article contributes to the field by presenting a comprehensive state-of-the-art review and case studies of the most common submerged arc welding high deposition modifications. Each modification is reviewed in detail, facilitating understanding and assisting in correct selection of appropriate welding processes and process parameters.

Real-Time Weld Process Monitoring

Welding defects result infailure of the machinery and other negative consequences. Therefore, they need to be detected as they appear to ensure efficient and high-quality production. There is a raising interest in the implementation of sensors to provide highly accurate and robust real-time welding process monitoring. This work describes the four most widely used techniques of welding process monitoring. These monitoring techniques are arc sensors, optical sensors, infrared sensors, and ultrasonic sensors. This work explains their principles of operation: discuss their advantages and limitations and give typical areas of application. Arc sensors, optical sensors, infrared sensors, and ultrasonic sensors are described in detail with the necessary figures and schemes in the first part of the present study. The physical background, the strengths and weaknesses, and real life examples of the sensing techniques are given in this part. The results of the research show that each sensing method has its specific features thatcan play an important role in certain welding applications. Arc sensors do not requireadditional equipment in the welding zone. Thisis why they can be used where operational space is limited. Optical sensors allow the observation of the weld pool behavior. Infrared sensors can create the temperature profile of the weld. Ultrasonic sensors usually have good resolution and can provide accurate data. This paper will help welding engineers to choose the optimal sensing equipment for aspecific industrial application.