Fretting wear tests of steels in hydrogen gas environment

Fretting wear tests in gross slip condition were performed in a highly gas-tight chamber, and the dew point of gas was measured and controlled. In hydrogen, wear scar was larger in high water content of 49ppm than in low water content of l.5 ppm. In nitrogen, wear scar was large in high water content. The effect of water content in surrounding gas can be seen in the appearance of the wear scars; wear scar boundary was irregular in small water content gases, while it was almost circular in high water content gases. As for the effect of exposure to high pressure hydrogen (40 MPa) and at 373 K, the wear scar on the exposed specimen was larger than that of intact one. These effects of impurity and exposure to high pressure hydrogen were consistent with the previous results. This is an abstract of a paper presented at the World Tribology Congress (Kyoto, Japan 9/6-11/2009).