Indian Journal of Science and Technology

Abstract

Objectives: To prepare a wear resistant surface and to induce compressive stress on the AISI 304L steel by depositing titanium-graphite powder in a matrix of AISI 308 steel. Methods/Statistical Analysis: The coating is deposited using manual metal arc welding (MMAW) process with a current value set at 125 amp and 70 volt. The alloy element titanium is added upto 1, 1.5 and 2% and carbon content is maintained at 0.3%. The coated samples are heated with oxy-acetylene flame and impact force is applied on the coated surface during heat treatment, to ensure penetration of the hard particles. Further, compressive stress is induced on the surface because of the applied impact force. The coated surface is finished in a surface grinding machine to obtain a flat smooth surface. Hardness assessment is carried out on the coated surface using Rockwell hardness measuring machine. Findings: A maximum hardness value of Rc55 is obtained for the sample containing 1% titanium and 0.3% carbon. Pin on disc experiment is conducted on the samples to estimate the wear rate. The Scanning Electron Microscopy (SEM) examination revealed the presence of various carbides in the alloy. Energy Dispersive X-ray Analysis (EDAX) is performed to find out composition of the coating. Application/Improvements: The wear resistant coating could be used in corrosive environment. Shafts can be arc deposited and compressive stress can be induced on the surface using a blunt tool fitted with the tool post of a lathe. This alloy can be used as a wear resistant coat and as a bearing material.  

Keywords: Austenite Grains and Oxides, Carbides, Intermetallic Compounds, Micrograph