Coating of valf surfaces with TIG welding method and investigation of wear charecteristics

In this study, surface of 1.4718 type steel, which is especially used in automotive valves, is coated with Cobalt based Stellite 1, Stellite F and Stellite 6 and Ni 60 alloys by using TIG welding. Samples, coated with given parameters, were worn on the pin on disc at room temperature and 300 0C. By the total wearing distance is 4400 m and the applied loads are 10, 25 and 40 N Samples were weighted after each 1100 m distance in each test.Another group of samples were worn at room temperature with 400 mesh Al2O3 abrasive. 10,5 m wearing distance and 10, 25 and 40 N load were used as wearing parameters.Tests showed that temperature, abrasive and applied load effect on abrasive characteristics. The amount of wear lost increase with increasing temperature, applied loads and wearing distance. Sample which is coated with Stellite 1, showed the highest wearing resistance and sample which is coated with Stellite F showed the lowest wearing resistance under all test parameters. It is also found that, especially Co, Cr and C in coating material increases the wearing resistance of valves. Furthermore, it is also found that wear lose all samples increases with increasing temperatures applied load and total wearing distance. It is also found that abrasive wears more than adhesive wears.Key Words: Valf, coating, abrasif wearing, adhesiv wearing, TIG welding, micro structure.