PSI - Issue 53

Daniel R. Galán-Rivera et al. / Procedia Structural Integrity 53 (2024) 407–415 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

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Fig. 3. Macrograph and detail of the tram rail repaired with “Material 1”

3.2. Material 2 This material is a corrosion-resistant metal powder, recommended for welding austenitic base metals having low carbon content. This powder is used for overlays of non-alloy, low-alloy and high-alloy steels and corresponding cast steels. It has more than 6% of Nickel (Ni), so it is softer than Material 1 avoiding cracking. The powder hardness is about 170HB, work hardened to 400HV (Table 2). During the set-up process, non-metallic inclusions have appeared in the previous macrographs (Fig. 4). To solve it, it has been enough to reduce the contribution of metallic powder There has been no cracking in any of the tests with this material, so it has not been necessary to preheat the base metal, although precautions have been taken limiting the cooling rate between layers.

Fig. 4. Macrograph and detail of the tram rail repaired with “Material 2 ”

3.3. Material 3 Material 3 is a martensitic chromium stainless steel powder. It has been optimized for wear resistance while still offering good corrosion resistance in general atmospheric and industrial environments. Coatings of this powder have good strength and reasonable impact properties. They also produce general purpose coatings that combine moderate to good wear and corrosion resistance, especially when heavy coating build-up is needed (Fig. 5). It is recommended for applications where mild abrasive grains, particle erosion, fretting and hard surface wear are a problem. They can also be used for recovering of grindable carbon and corrosion resistant steels. This powder was the most difficult to obtain a correct set up, mainly because it was very difficult to avoid the longitudinal silicates. On the other hand, during the cooling stages, a transverse cracking occurs. To eliminate the mentioned defects, several strategies were taken having different results: