Ivanov V. Theoretical and technological fundamentals for increasing the efficiency of the electric arc overlaying process on the basis of modeling of the weld pool formation

The purpose of the work is to increase the efficiency of the electric arc surfacing welding on the basis of mathematical modeling of the formation of the weld pool by creating technology and equipment for the implementation of the technological process with control of the composition and properties of the deposited layer The object of research is the process of formation of a welding pool at electric arc surfacing. The subject of research is the functional dependence of the evolution of the base metal penetration zone and the ways of regulating its basic parameters during electric arc surfacing. Methods of research: methods of mathematical modeling; chemical and spectral analysis, mechanical testing to determine the composition and properties of weld metal; optical microscopy to study the structure of the weld metal and the seam zone; investigation of the surfacing process using an automated research complex based on a data collection board. A theoretical generalization and a new solution to increase the efficiency of the electric arc welding process by controlling the composition and properties of the deposited layer based on mathematical modeling of the formation of a non-stationary welding pool. For the first time a mathematical model of a penetration zone formation in time with a stationary heating source is completed, which ends in a period of time up to 10 s, with an increase in the speed of surfacing in the range of (2,8÷11)•10-3 m/s reduces this period by 12÷35%. It is established that the shape of the melting front curve in the studied interval of the input data can be expressed as a nonlinear function in which the parameters of the front motion depend on the feed rate and the diameter of the electrode. A new approach is proposed to calculate the depth of the penetration zone when surfacing with a strip electrode under a layer of flux, which takes into account the phenomenon of movement of the welding arc at the end of the strip electrode.