PSI - Issue 36

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

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The dependence of surface hardness of the applied layer is also obtained. The increase in surface hardness is recorded at silicon content of 0. 6… 1. 3% in the presence of 0…0 .15% and 0. 45…0 .60% of aluminum in the surfacing material. There are two areas of extreme hardness values. It should be noted that the presence of 0. 2… 0.5% of aluminum in the surfaced material slightly reduces the hardness increase, but equalizes the discrepancy of its average values. For example, at constant silicon content of 0.1%, the increase in aluminum content from 0 to 0.6% results in the decrease of the average cross-sectional hardness from 62 to 60 HRC, i.e. only by 3%. At silicon content of 1.8% there is the decrease of average surface hardness from 62 to 52 HRC, i.e. by 16.1% Mathematically, the dependences of the change in surface hardness of the applied layer can be represented as follows:

2 2 max HRC1 = 58.1 13.03·Si – 25.03·Al – 7.11·Si –1.29 9·Si·Al 37.88·Al + +

(4)

2 2 min HRC1 51.41 17.44·Si –16.45·Al – 9·Si – 2.73·Si· Al 27.2·Al = + +

(5)

2 2 mid HRC1 54.75 15, 23·Si – 20.74·Al –8.054·Si – 2.01 6·Si·Al 32.55·Al = + + (6) Thus, the recommended ranges of Si and Al content in the applied layer, at which the maximum values of hardness of the deposited layer surface could be reached, are determined: for silicon this the range is from 0.60 to 1.22%, and for aluminum the ranges are from 0 to 0.10% and from 0.50 to 0.60%. It should be noted that the discrepancy of surface hardness values is lower than the cross-sectional hardness discrepancy and reaches only 3.3% in the recommended area and 13.3% maximum at silicon content of more than 1.75%.

cracks (taking into account the weighting facto)r n c = 303,6685+221,1414*x-1786,6234*y-156,157*x*x+419,1023*x*y+1879,5327*y*y

0,6

0,5

0,4

0,3

Al

0,2

350 300 250 200 150 100 50 0

0,1

0,0

0,2

0,4

0,6

0,8

1,0

1,2

1,4

1,6

1,8

Si

Fig. 4. Dependence of cracks formation intensity on the content of silicon and aluminum in the surfacing materials.