Unique Wear Reduction By Using Superexpanite® Hardening On AISI 316L Austenitic Stainless Steel!
AISI 316L stainless steel wear test G133
Wear is a pervasive problem for any kind of stainless steel, especially for the austenitic grades. In those alloys, Nickel is added not only to improve corrosion resistance but primarily to stabilize the FCC crystal structure. High ductility and toughness of these alloys, originating from the specific properties of FCC structure, provides good formability at the expense of hardness, and with that, of wear resistance. Based on results of a standardized test for wear resistance of materials, the reduction in wear for austenitic stainless steel with the SuperExpanite® surface hardening treatment is truly remarkable and shows that Expanite® is the leading solution to drastically improve the lifetime of your parts and products!
Ball-on-flat sliding wear test (ASTM G133)
The ASTM G133 test geometry involves a spherical counterpart, sliding in a reciprocating motion with a constant force of 25N, for a total distance of 100m. The resulting wear track is both visually inspected and measured with a profilometer. The latter yields a digital profile – a 2D cross-section of the wear track, from which the wear depth and volume can be measured. In this study, two sets of samples made with AISI 316L austenitic stainless steel, one without hardening process applied and one treated with SuperExpanite® hardening, were tested against 100Cr6 counterpart (bearing steel with hardness above 800HV).
The test results
The tracks visible in Figure 2 were made during the test with an amplitude of 10mm in ambient temperature and without lubrication. The wear marks on the left photograph are superficial and can be seen as polishing of the SuperExpanite® surface. The observed wear depth of 2 to 6µm is not detrimental to the hardened layer. On the right-hand side the untreated test sample with wear tracks 4-6 is presented and shows severe wear.