The effects of boronizing on the surface and fatigue properties of PM steel


Varol R., Eksi A., Bedir F.

METALL, cilt.57, ss.636-639, 2003 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 57 Konu: 10
  • Basım Tarihi: 2003
  • Dergi Adı: METALL
  • Sayfa Sayıları: ss.636-639

Özet

The aim of this study was to investigate the effects of boronizing on the surface hardness, microstructure, fatigue strength, and wear property of PM steel. ASC 100.29 grade (Hoeganaes) Fe-based powder was cold compacted into a prismatic shape with 6.9 Mg/m(3) nominal density using a single action press. The prismatic blanks were then sintered at 1120 degreesC for 30 minutes. The sintered blanks were machined into fatigue and wear test specimens. Finally, boronizing was applied to the fatigue and wear test specimens using EKabor 3 powder as boronizing agent at 900degrees C for 2 and 4 h. Wear tests were carried out by means of a pin-on-disc tester against 400 grit SiC abrasion paper. Fatigue tests were performed ons Wonler-type rotating bending fatigue test machine at room temperature. The results showed that boride layers with thickness values of 140 mm and hardness values of 1850 HV were formed on PM steel specimens boronized PM steel was lower than in as-sintered PM steel indicating that the boronized PM steel has higher wear resistance than as-sintered PM steel. It was also concluded that the boride layer thickness increased with boronizing time. The fatigue strength of PM steel boronized at 900 degreesC for 4 h was 12% higher than of as-sintered PM steel.