HYBRID SURFACE ENGINEERING OF IMPULSE FACE SEALS FOR NUCLEAR POWER EQUIPMENT

Abstract

This study investigates the formation of combined wear-resistant coatings on steel rings of face impulse seals (FІS) aimed at improving their operational performance under aggressive environments and radiation exposure. A multistage technology is proposed, including electrospark alloying using a W-Zr-B electrode system, plasma nitriding, deposition of copper and carbon-containing layers, and final treatment by non-abrasive ultrasonic finishing (NAUFT). The formation of a gradient-strengthened layer without a “hardness drop” has been established, along with an increase in hardness up to 970…1490 HV and a reduction in surface roughness to Ra = 0.2…0.4 μm. The obtained results confirm the effectiveness of the proposed approach for FІS applications.