PSI - Issue 23

Ivo Černý et al. / Procedia Structural Integrity 23 (2019) 493 – 498 Ivo Černý / Structural Integrity Procedia 00 (2019) 000 – 000

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Fig. 1. S355 steel plate with three configurations of additive laser welded H13 steel layers.

The hardness was evaluated as Vickers HV 10. Four dependencies were measured, namely the course from the surface additive layers to the depth, to the base material for both one layer and two layers welds and the horizontal courses at the depth approximately 0.5 mm under the surface, also for both the single layer and two layers cases. The fatigue tests were performed using small specimens of the length 50 mm and nominal cross section approximately 9 x 9 mm and 7 x 7 mm for specimens with the additive layers and specimens of base material, respectively. The position of the specimens in relation to the additive layers was perpendicular. The loading was of the three point bend type, test span 35.2 mm, load frequency 40 Hz. The tests were performed on a simple mechanically controlled SCHENCK PHG machine with the load capacity up to 3500 N.

3. Results and Discussion

3.1. Macrostructure

Macrostructure of the single additive welded track in two different positions of cross section is documented in Fig. 2 a,b, macrostructure of a single and double additive layers in their cross sections in Fig. 3 a,b, respectively.

5.000 mm

a) b) Fig. 2. Macrostructure of single additive track in cross section at two different positions (a) with visible exsolution bends, (b) with more homogeneous structure and deeper penetration to base material.