TRIBOCORROSION BEHAVIOUR OF 420 MARTENSITIC STEEL IN ALLIUM CEPA EXTRACTS UNDER LOW LOADS

<ns3:p>The paper presents the results of tribocorrosion resistance tests of AISI 420 stainless steel in onion juice. The study constitutes one of the stages in selecting a suitable material for the production of onion-cutting knives. The main objective was to identify the optimal heat treatment conditions to minimize tribocorrosive wear. Tribocorrosion tests were carried out using a ball-on-plate configuration under a low normal load of 1.7 N, simulating the operating conditions of an onion-cutting knife. Two heat treatment variants of quenched AISI 420 steel were investigated: tempering at 400 C (medium tempering) and tempering at 200 C (low tempering). The results showed that the highest hardness (approximately 54 HRC) was obtained after low-temperature tempering. However, the samples tempered at 400 C, which exhibited slightly lower hardness (about 51 HRC), demonstrated better tribocorrosion resistance in onion juice under low loads. In contrast, the harder samples (54 HRC) showed reduced corrosion resistance in onion juice and slightly higher susceptibility to cracking, resulting in lower tribocorrosion resistance compared with the samples tempered at 400 C.</ns3:p>