TY JOUR TI The Influence of Laser Hardening on the Metallographic and Tribotechnical Properties of Class 55 Steel Used in Diesel Locomotive Camshafts KW Laser hardening KW microhardness KW microstructure KW coefficient of friction KW wear rate KW wear resistance JO Bulletin of scientific research results AU Biryukov, V.P. AU Miryaha, A.N. AU Yakubovsky, A.A. AU Kulakov, O.I. AU Goryunov, Y.A. PY 2025 IS 2025 PB FSBEI HE "Emperor Alexander I St. Petersburg State Transport University"