Friction and Wear of Ferrous Materials in a Hydrogen Gas Environment

A novel technique was developed to control the concentration of water between 0.1 - 20 ppm and of oxygen between 0.3 - 2 ppm in hydrogen over a pin-on-disk apparatus. The developed technique simulates commercially available hydrogen gas at the point of use. This hydrogen usually contains sub-ppm to single-digit ppm levels of water and oxygen. The influence of impurities on the tribological properties of hardened chromium steel (JIS SUJ2) was obvious under the studied conditions, while the influence on austenitic stainless steel (JIS SUS316L) was not significant by comparison with that found in our previous study concerning higher water concentrations. The coefficient of friction of JIS SUJ2 increased with a decrease in the water concentration even at the smallest concentrations investigated in this study