Research of the method of selective laser sintering for strengthening soil tillage working organs

One of the technologies for increasing the service life of working bodies is applying a hardening layer with a material that is more resistant to wear. The study was conducted to evaluate the efficiency of the selective laser sintering (SLS) method for hardening soil-cultivating working bodies. The plasma-powder surfacing method was considered as a comparison option. The studies were conducted on a circular soil test bench, which was a rotor with racks rotating in a cylinder filled with an abrasive medium for rapid surface wear, on which samples were attached. Four experimental samples made of 30KhGSA steel were studied. The dimensions of the hardening layer were determined by calculation. After that, it was applied with P6M5 metal powder using the SLS method to 2 samples, one was hardened before heat treatment, the second after. Similarly, but using FBH-6-2 powder, 2 samples were made using plasma-powder surfacing. The bench test duration was 152 h. The linear wear of the samples when hardened by the SLS method before heat treatment was 1.3 mm, after heat treatment – 0.83 mm, by the plasma method – 1.1 mm and 1.2 mm, respectively. The hardness values that stand out from the others, with the SLS method are observed in the hardening layer zone: the sample before heat treatment is 65 HRC, after it – 73 HRC. With the plasma method, the difference in hardness is observed in the zone near the hardening layer: before heat treatment – 45 HRC, after – 35 HRC. The use of the selective laser sintering method for hardening the blade part of the experimental samples ensured a decrease in the consumption of metal powder, in comparison with the plasma method, by 32 %, an increase in wear resistance of the samples according to the calculated data – by 26 %, on the circular soil stand – by 24 %.