Steel surface modification by pulsed air arc treatment

Pulsed air arc treatment (PAAT) was used to modify the surface morphology and phase composition of 5010 and 01 steel. The arc produced local heating and eroded the steel surface forming craters, and the subsequent modification depended on the crater density. X-ray diffraction showed that the volume fraction of ferrite decreased while that of austenite increased with crater density. Cementite was practically absent in 5010 steel, while its volume fraction in O1 steel increased with crater density. PAAT increased the microhardness of the surfaces by 10–40% over that of the virgin surfaces. PAAT increased the lifetime of a lubricant film applied to the surface by more than an order of magnitude, by forming craters on the surface which retained the lubricant.