EFFECT OF THERMOCYCLIC ELECTROLYTE-PLASMA TREATMENT PARAMETERS ON THE STRUCTURAL-PHASE STATE AND TRIBOCORROSION BEHAVIOR OF 12KH1MF STEEL

30.09.2026

In this work the influence of regimes of thermocyclic electrolyte-plasma treatment (TEPT) on structure-phase state, microhardness and tribocorrosion behavior of 12Kh1MF heat resistant low alloy steel for power plant steam pipelines and boilers is investigated. TEPT was performed in 10 % aqueous solution of Na2CO3. Voltage varied from 300 V (30 А) to 150 V (8 А) every 5 s. Three regimes were considered at maximum surface temperature from 800 to 900 °С. Samples were studied by SEM, X-ray phase analysis, Vickers microhardness test, ball-on-disk tribology test and neutral salt spray corrosion tests. TEPT has a layered structure - thermocyclic hardening zone, heat affected zone and base material. Hardened layer thickness is from 400 to 600 μm according to regimes. Ferrite pearlite initial structure transforms into martensite (α'-Fe) with Fe3C carbides. Consequently, microhardness increases from 205 to 345-373 HV 0.1 (almost 1.7-1.8 times). Friction factor reduces from 0.627 to 0.596-0.617; wear intensity decreases up to 1.8-fold. Corrosion speed is reduced from 0.0024 to 0.0013-0.0019 mm / year. The optimal balance between friction and corrosion resistance was achieved in regime no 2. The maximum values of hardness and wear resistance were obtained for regime no 3. The obtained results indicate the effectiveness of TEPT on localized surface hardening of 12Kh1MF steel components working in abrasive and corrosive conditions.

thermocyclic electrolyte-plasma treatment, 12Kh1MF steel, heat-resistant steel, martensite, microhardness, wear resistance, corrosion resistance.