PSI - Issue 36

Valerii Peremitko et al. / Procedia Structural Integrity 36 (2022) 106–113 Valerii Peremitko et al. / Structural Integrity Procedia 00 (2021) 000 – 000

112

7

The non-uniformity of the hardness values applied in cross section and on the surface is an important fixed factor. That happens due to the presence of aluminum in metal. So, another important fact is the ability to adjust this value due to the content of this element. Influence of Si and Al content on the formation of defects in the applied layer Defectation of 100x100 mm samples was performed by visual inspection and measurement. In order to bring the influence of crack opening on the efficiency of the applied layer to single indicator, the weighting factor was introduced k c : 1. 0 for cracks ≤ 0 .10 mm; 1. 15 for cracks ≤ 0 .20 mm; 1. 30 for cracks ≤ 0 .30 mm. Statistical analysis of the obtained data shows that the smallest amount of cracks or their complete absence can be expected on the samples surfaced with wires / tapes, where the composition of the metal of pure surfacing includes 0. 26… 0 .42% of aluminum at silicon content of 0. 20… 1 .80% and 0. 26…0 .60% at silicon content of not more than 0.70% (see fig. 4). Mathematically, the dependence of the intensity of formation of cracks on the content of silicon and aluminum in the surfacing materials (the claimed compositions of pure surfacing, without mixing) can be represented in the following way:

2 2 c n 303.67 221.1·Si –1786.6·Al –156.2 Si 419.1· Si·Al 1879.5·Al = +  + +

(7)

pores (taking into account the weighting facto)r pore = -16,3998+27,5956*x+117,9424*y-12,59*x*x-39,9307*x*y-147,0402*y*y

0,6

0,5

0,4

0,3

Al

0,2

0,1

0,0

10 0

0,2

0,4

0,6

0,8

1,0

1,2

1,4

1,6

1,8

Si

Fig. 5. Dependence of the pore formation intensity on the content of silicon and aluminum in the surfacing materials.

Statistical analysis of data on the amount of pores and friability showed that the greatest risks of pore formation occur in the case of surfacing with wire/tape, where the composition of pure surfacing includes silicon in the range of 0.42…0.82% with aluminum content of 0.25…0.40% (fig. 5). It should be noted that a significant increase in the number of pores is observed in surfacing with the wire having small diameter of 1.6 mm, and in surfacing with the wire having diameter of 2.0 mm, there are no pores at all. This fact requires special investigation. Mathematically, the dependence of the pore formation intensity on the content of silicon and aluminum in the surfacing materials can be represented as: