PSI - Issue 23

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

498 6

600

500

400

300

Single layer Single layer runout Double layer Double layer runout BM BM runout

200

a)

Stress range (MPa)

100

0

b)

1.E+03

1.E+04

1.E+05

1.E+06

1.E+07

1.E+08

Number of cycles

Fig. 7. a) Fatigue cracks in surface defects, b) sumace defects in additive selded layers

Fig. 6. High-cycle fatigue S-N curves

4. Conclusions

The study of the structure and properties of specific additive welding of powder H13 steel on structural base S355 steel indicated and confirmed significant advantages of the technology. The microstructure was stable and homogeneous, hardness of the layers was excellently high and reproducible. Even fatigue properties, particularly in the region of fairly high stress range, were encouraging. The technology with the parameters used resulted in an occurrence of microscopic surface defects – lack of fusion, which reduced endurance limit. Further optimisation from this point of view would be needed, if high cycle loading of the additive welded components was expected.

Acknowledgement

The support of the grants TG03010032 and LTE119009 is acknowledged.

References

Capello, E., Colombo, D., Previtali, B., 2005. Repairing of sintered tools using laser cladding by wire. Journal of Materials Processing Technology 164 – 165, 990 – 1000. Costa, J.M., Ferreira, J.M., Capela, C., 2009. Fracture Toughness of the Heat Affected Zone on Nd-YAG Laser Welded Joints. Engineering Failure Analysis 16, 1245 – 1251. EN 10025-2 Standard, Part 2. 2004. Technical Delivery Conditions for Non-alloy Structural Steels. EN ISO 18265 Standard, 2014. Metallic Materials, Conversion of Hardness Values. 77 p. http://www.joostdevree.nl/bouwkunde2/jpgs/staal_23_standaarden_s355_european_standard_steel.pdf Pleterski, M., T. Muhič, T., Podgornik, B., Tuš ek, J., 2011. Blanking Punch Life Improvement by Laser Cladding. Engineering Failure Analysis 18, 1527 – 1537. Steen, W.M., Watkins, K., 2003. Laser Material Processing. Springer, New York, 408 p. Sun, S.D., Liu, Q., Brandt, M, Luzin, V., Cottam, R., Janardhana, M., Clark, G., 2014. Repair and Manufacturing of Military Aircraft Components by Additive Manufacturing Technology. Materials Science and Engineering A 606, 46 – 57. Sun, Y., Sunada,H., Tsujii, N., 2001. Crack Repair of Hot Work Tool Steel by Laser Melt Processing. ISIJ International 41,1006 – 1009. Telasang, G., Majumdar, J.D., Wasekar, N., Padmanabham, G., Manna, I., 2015. Microstructure and Mechanical Properties of Laser Clad and Post-cladding Tempered AISI H13 Tool Steel. Metallurgical and Materials Transactions A 46A, 2309-2321.