Plasma hardening of corrosion-resistant steel

Abstract

The structure, phase composition and hardness of a 20X13 steel coating treated with two consecutive passes of a plasma arc are studied. It is shown that plasma treatment makes it possible to obtain martensite with a significant (30-50 %) share of permanent austenite in the structure of the local hardening zone. In this case, the hardness of the heat-strengthened blanket is 650-700 HB. The total depth of the local hardening zone with the modified structure reaches one millimeter. The study shows that a homogeneous structure with periodically changing phase composition and hardness develops in the surface layer of 20X13 steel, heat-treated plasma arc. in this case, the plasma arc must pass sequentially with a certain degree of overlap of local quenching zones. It is obvious that by adjusting the parameters of the processing conditions (the current of the plasma arc, the speed of its movement, the degree of overlap of local quenching zones), it is possible to purposefully form a certain structural-phase state of the surface layer with properties that best meet the operating conditions. © Published under licence by IOP Publishing Ltd.