Investigation of annealed martensitic stainless steel under dry sliding conditions
摘要
The primary goal is to investigate the effect of vacuum annealing on martensitic stainless steel. Stainless steel offers high corrosion resistance and is widely available at a low cost. It is an alloy with iron, chromium and a material for resisting corrosion. The applications of martensitic stainless steels are limited and through proper heat treatment, the applications are extended in manufacturing of turbine parts, medical equipment, and household appliances. Martensitic stainless steel (MSS) are inherently brittle and hard, lacking ductility; this can be mitigated by annealing to achieve a better balance between hardness, ductility. The Vacuum annealing process reduces the hardness, improves ductility, relieve internal stresses and also soften the metal. As per ASTM G99 standards, AISI420 samples were prepared in cylindrical shape of 30 mm length and 10 mm diameter by using a lathe machine. Three samples were annealed to 728 °C, 828 °C, 928 °C and holded to 60 min, furnace cooled at 300 C/hour and was named as AN1, AN2, AN3. The annealed samples were subjected to wear testing under dry sliding condition using a pin on disc tribometer. A constant load of 100 N, speed of 1000 rpm were applied on the specimens, to evaluate the wear resistance. Then the samples are undergone to the hardness test by Rockwell hardness machine and subjected to metallography studies using Scanning Electron Microscope, to evaluate the Surface Morphology of annealed and untreated sample. Wear behavior of untreated and annealed samples were compared, phase changes was observed.