PSI - Issue 30

Pavel Zhilin et al. / Procedia Structural Integrity 30 (2020) 209–215 Pavel Zhilin et al. / Structural Integrity Procedia 00 (2020) 000–000

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2. Theoretical and experimental results

Fig. 2 shows the calculation results of (Q) heat input values [kJ/mm] for hot wire submerged arc cladding in accordance with the following formula: ��� where U a and U hw are arc and hot wire voltage values [V]; I a and I hw are arc and hot wire current values [A]; V is cladding speed [mm/min]. 60 1000 ) ) ( (       v I Q U I U hw hw a a

Fig. 2. Heat input vs the relative amount of heated AFW.

Fig. 3. Schemes of the AFW feeding into the front (a) and back (b) weld pool parts.

The calculation results are given for the filler wire feeding into the front weld pool part (Fig. 3, a). Their analysis enables to conclude that in order to achieve a similar level of productivity, it is necessary to use twin arc cladding with a twofold increase in heat input (over 14 kJ/mm) instead of less than 10% enhance in the presented case. Fig. 4–6 show the results of the experimental studies of the effect of various amounts of filler wire on the profiles of welds and deposited beads. Automatic hot wire submerged arc welding and cladding have significant advantages over the conventional processes. In particular, the deposition rate increases by 1.5…2.0 times while the penetration depth and the ratio of the base and filling metals reduce by 2…3 times. Based on the results of the full factorial experiment, mathematical models have been developed. They include dependences of the weld pool length, relative slag mass, penetration depth, weld bead height, cladding cross-section area, the ratio of the base and filling metals, dimensions of the heat-affected zone (HAZ) depending from the parameters of the welding and cladding processes using AFW. Also, a methodology has been proposed for calculating these parameters and assessing their effect on the basic mechanical properties of the formed wear- and corrosion-resistant coatings and various welded joints such as presented by Konischev et al. (1987), Konischev and Zhilin (1988), Konischev et al. (2015), Zhilin and Gerasimov (2019).