PSI - Issue 20

Sivtsev M.N. et al. / Procedia Structural Integrity 20 (2019) 148–153

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Sivtsev M.N. et al. / Structural Integrity Procedia 00 (2019) 000 – 000

equipment used, their introduction into the structure of the special microprocessors and microcontrollers that provide control algorithms designed to maintain the required process parameters. In such systems, the device used to ensure maintenance of the welding process on the joint, stabilization speed of modes - the speed of movement relative to the work piece, maintaining the desired angle of inclination of the electrode. Currently, the traditional stationary processes of welding and surfacing (arc, electroslag, plasma) is almost exhausted their technological capabilities. Concentration heat energy of welder equipment is not solved, and cannot solve many problems, including problems of productivity and improving weld quality by Paton B.E., Sarayev Yu.N., Lebedev V.A. (2013). The conceptual approach developed and implemented ISPMS RAS, based on the introduction of new welding techniques to ensure the operational reliability of steel structure, showed perspective applications of adaptive pulse arc welding techniques. The use of adaptive pulsed-arc welding involves the control of all the stages of forming a welded joint (welding arc, melting and transfer electrode metal to the weld pool, the crystallization of the weld metal from the melt) using a feedback channel, which control the basic characteristics of the energy production process deeply studied Sarayev Yu.N. (2010) and Sivtsev M.N., Sleptsov G.N. (2014). Research of welding features at low climatic temperatures revealed that the ambient temperature affects influence the flow of processes in the welding arc, the kinetics of thermal and thermal deformation cycles thermal welding, as well as the final distribution of alloying elements in the weld metal and fusion zone that proved Larionov V.P. (1998). Therefore, the study of features influences the energy parameters of the adaptive pulse-arc welding (APW) on the heat affected zone formation (HAZ) of the welded joint at low temperatures is an important task. The purpose of the initial phase of this study is to investigate the heat affected weld zones obtained by adaptive pulse-arc welding for structural steels at ambient temperatures and +20 0 C - 42 0 C. 2. Materials and Experimental Procedure In the present work to identify the current pulses influence on the formation HAZ hold on identical technological parameters of the welding process, with the following welding modes: - stationary mode I w =140A, U w =28-30V, l w =80mm; - adaptive pulse-arc welding mode (APW) are shown in Table 2. Stationary mode of welding performed by the standard technology for manual arc electrodes on the welding rectifier VD-306E. Welding performed in a pulsed mode at a specialized installation UDI-205, realizing the adaptive process for producing welded joints. The welding parameters were recorded on a digital recorder welding parameters AWR 224MD (Fig. 1). Surfacing in one pass, producing pre-calcining electrodes UONI 13/55 type E7016, diameter 3.0 mm, according to GOST by GOST 33258-2015 (2016), on a plate of structural steel of ordinary quality St3SP at temperatures of -42 0 C and +21 0 C.

Fig. 1. Waveform pulsating current adaptive pulse-arc welding.