scholarly journals Determining the dynamics of carbon monoxide formation during gas welding processes

2021 ◽  
Vol 5 (10 (113)) ◽  
pp. 33-39
Author(s):  
Viacheslav Berezutskyi ◽  
Inna Khondak ◽  
Nataliia Berezutska

This paper reports a study of the air medium where welding processes take place, with special attention paid to the evolution of carbon monoxide (CO) in the working medium in the process of gas welding. Plots were constructed and polynomial dependences were obtained to show a change in the concentration of carbon monoxide in the air of the working area during gas welding. It was confirmed experimentally that the concentration of carbon monoxide exceeds the permissible sanitary and hygienic indicators MPC (20 mg/m3) during gas welding. As a result of the experiment, the effectiveness of the use of an additional device was proven, namely an umbrella gas concentrator, in order to capture welding gases that are formed during gas welding. It was established that the MPC is exceeded under certain working conditions and welding wire. The carbon monoxide formation during gas welding was analyzed; these processes were compared with electric arc welding. The mathematical dependences derived make it possible to assess the risks of the welders’ work and conclude that the electric arc welding is characterized by a much higher rate of CO evolution from the beginning of the welding process (8.5 mg/s), that speed then decreases over 20 s by 2 times (to 4.5 mg/s). In 90 s, the speed becomes constant, to 2 mg/s. In comparison, gas welding has almost the same rate of CO formation, namely 0.3–0.9 mg/s. By changing the types of welding wires used in gas welding and taking into consideration the type of material that needs to be welded (including the period of its use), it is possible to influence the volume of CO emissions entering the working area and an employee’s respiratory area

2006 ◽  
Vol 113 ◽  
pp. 29-33
Author(s):  
Algirdas Dambrauskas ◽  
Bronius Karaliunas ◽  
D. Shulskis

The main flaws of electric arc welds and factors determining the quality of the welded seams are considered in this paper. In practice, welding tools and their control systems are affected by some external factors causing deviation of the weld’s quality from the specified values. Currently used control systems of welding tools do not always satisfy the requirements for quality of welded joints. Major principles of developing the adaptive control system of the welding tool are considered here and the developed functional and block diagrams of microprocessor system are presented. General equations describing the welding process are also provided and the obtained transfer function of a closed system is described.


2018 ◽  
Vol 2018 (2) ◽  
pp. 30-33
Author(s):  
G.V. Kuzmenko ◽  
◽  
V.M. Taganovsky ◽  
V.L. Sidorenko ◽  
◽  
...  

Author(s):  
Pavel Layus ◽  
Paul Kah ◽  
Viktor Gezha

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.


2011 ◽  
Vol 403-408 ◽  
pp. 1804-1807
Author(s):  
Ning Zhao ◽  
Shao Hua Dong ◽  
Qing Tian

In order to optimize electric- arc welding (ERW) welded tube scheduling , the paper introduces data cleaning, data extraction and transformation in detail and defines the datasets of sample attribute, which is based on analysis of production process of ERW welded tube. Furthermore, Decision-Tree method is adopted to achieve data mining and summarize scheduling rules which are validated by an example.


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