PSI - Issue 36

5

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

110

There is the increase in cross-sectional hardness with the increase in silicon content to 1%. All graphs show the range of extreme hardness values at silicon content of 0.6 … 1.2%. It should be noted that the increase in the applied aluminum material slightly reduces the increase in hardness. For example, at constant silicon content of 0.3% the increase in aluminum content from 0 to 0.6% results in the decrease of the average cross-sectional hardness from 57 to 49 HRC, i.e. by 14% (Fig. 3).

average hardness across the cross section of the depos ited layer HRC mid = 44,9833+29,2245*x-5,1681*y-17,5944*x*x+15,769*x*y-18,4782*y*y

0,6

0,5

0,4

0,3

Al

0,2

0,1

58 54 50 46 42

0,0

0,2

0,4

0,6

0,8

1,0

1,2

1,4

1,6

1,8

Si

Fig. 3. Dependence of hardness on the cross section of the applied layer HRC mid .

When silicon content in the surfaced material is more than 1.1%, there is the decrease in hardness from 60 to 46 HRC (on average by 23.3%). Mathematically, the dependence of the change in hardness on the cross section of the applied layer can be represented as follows:

2 2 max HRC 49.47 23.91·Si – 7.66·Al –14.01·Si 12.4·Si·Al –8.9·Al = + +

(1)

2 2 min HRC 40.49 34.53·Si – 2.66·Al – 21.18·Si 19.09·Si ·Al – 28.06·Al = + +

(2)

2 2 mid HRC 44.98 29.2·Si – 5.17·Al –17.59·Si 15.77·Si·Al –18.48·Al = + + (3) Thus, the range of parameters of the maximum values of hardness in the cross section of the applied layer is determined: the silicon content within the range of 0. 65… 1.25% with aluminum content of 0. 15… 0.35%. It should be noted that the range of hardness values in cross section reaches 37.7% (minimum values). The discrepancy between the values of the average hardness in cross section is 27.6%. It should be also noted that the lowest hardness values can be obtained when the silicon content in the surfacing materials is more than 1.75%.