Manufacturing Technology Today

C. K. Srinivasa ¹, C. S. Ramesh ², S. S. Avadhani ¹, S. K. Prabhakar ¹

Affiliations
1 Central Manufacturing Technology Institute, Tumkur Road, Bangalore, IN
2 Dept of Mechanical Engg., PES Institute of Technology, Bangalore, IN

Abstract

Iron and iron-SiC (NiP-coated) composites with 1, 2, 3 and 5 wt % of SiC, were produced by Direct Metal Laser Sintering (DMLS) p rocess. Sintering parameters namely the laser power, hatch width, hatch spacing and layer thickness were maintained at 180W, 5mm, 0.2mm, 0.05mm respectively while the laser scan speed was varied from 50 to I25mm/s in steps of 25. Salt spray test method was adopted to study the corrosion behaviour of laser-sintered parts. Salt spray tests were conducted in 5.0 % NaCl solution for durations of 24, 48 and 72 hours. Laser scan speed and wt. % of SiC had a significant influence on the density and corrosion behaviour of sintered iron and its composites. At all test durations studied, iron-SiC (NiP-coated) composites have exhibited excellent corrosion resistance when compared with iron.

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S. S. Avadhani ¹, Srinivasa Rao ¹

Affiliations
1 Material Testing/TPM Dept. CMTI, Tumkur Road, Benagaluru, IN

Abstract

The usual mechanical properties of steels are strongly linked to the complex microstructure obtained after their heat treatment, which is generally performed to achieve good hardness and/or tensile strength with acceptable ductility. The purpose of this study is to identify the ischolar_main cause of failure and preventive action for the rail component made out of Oil Hardening Non Shrinking (OHNS) (O1 grade) used in machine tool applications. The detailed investigation is made to identify the ischolar_main cause and to overcome such failure by adopting appropriate heat treatment practice. The investigation reveals that the failure of rail component is due to inappropriate heat treatment practice and the presence of sharp corners in the component.

Keywords

Failure Analysis, OHNS Steel, Heat Treatment, Quench Cracks, NDT.

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S. S. Avadhani ¹, Champuri Srinivas Rao ¹, C. J. Kumara ¹

Affiliations
1 Total Prod. Maintenance (TPM) Dept., Central Manufacturing Technology Institute (CMTI), Bengaluru, IN

Abstract

Hard chrome plating is widely used for various applications requiring wear and corrosion resistance. The quality of plating is influenced by applied current, relative position of anode & work piece, bath solution composition & concentration, temperature. The present work is focused on design & development of fixtures for holding anode with a view to produce uniform coating on internal surface of work piece made out of 17-4-PH steel. The plating was carried out with and without concentric position of anode. The quality of coating in respect of uniformity was assessed by measuring coating thickness. The results show that the uniformity in coating is achieved by the use of fixture for concentric position of anode.

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