Characteristics of AISI 420 And AISI 301 Stainless Steels Coatings Obtained by Thermal Spraying

In this study, AISI 301 and AISI 420 stainless steels were deposited on an AISI 4135 substrate using the wire arc spray process (WASP). X-ray spectrum analysis revealed the presence of a body centred cubic (bcc) structure in both coatings. In particular, the AISI 301 coating showed the additional identification of chromium carbide Cr7C3. Conversely, the AISI 420 coating manifested the presence of a body centred cubic (Fe, Cr) structure, which is indicative of the formation of solid solutions and the development of carbides, due to significant statistical variations in the composition. Vickers HV0.3 microhardness measurements were carried out and showed that the AISI 420 coating had a higher hardness (549 +/- 17 HV0.3) compared to the AISI 301 coating (383 +/- 18.75 HV0.3). The formation of oxides, a phenomenon not present in the AISI 301 coating, is attributed to this difference in hardness. The wear resistance of the AISI 301 and AISI 420 stainless steel coatings was evaluated at different sliding speeds (0.5 and 1 m/s) and under different applied loads, its expose the AISI 420 had less wear rate (2,64E-08 mg/m +/- 1,66667E-7) than AISI 301 (1,13E-05 mg/m +/- 5,63E-07) . Moreover, the corrosion behaviour of specimens was determined. It is noteworthy that AISI 420 coating provides 93.5% effective protection higher than that of AISI 301 coatings.