METHOD OF MANUFACTURING SPINDLE FROM STEEL FOR PIPELINE FITTINGS Russian patent published in 2010 - IPC F16K1/02 B23P15/00 C25F3/16 C23C14/48 

FIELD: engineering industry.

SUBSTANCE: method involves heat treatment, mechanical treatment with thread formation, polishing, ion implantation and application of multi-layer coating. Polishing is performed with electrolyte-plasma method. There performed is multiple-stage ion implantation of at least one ion chosen from the following group of chemical elements: Cr, Y, Yb, C, B, Zr, N, La, Ti, or their combinations at ion energy of 0.2-300 keV and ion implantation dose of 10¹⁰ to 5·10²⁰ ion/cm². After ion implantation is completed, there performed is post-implantation annealing at temperature of t=400-700°C during 1.5-3 h. Multi-layer coating containing layers of nitrides Me-N, carbides Me-C and carbonitrides Me-NC, where Me - Ti, Zr, TiZr, N - nitrogen, C - carbon, is applied.

EFFECT: improving reliability and increasing life time of pipeline fittings due to reduction of spindle corrosion.

27 cl, 3 tbl, 1 ex