Journal Articles

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Author: search.filters.author.Rao, D.S.Has files: No

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    Surface hardening of high-strength low alloy steels (HSLA) dual-phase steels by ball burnishing using factorial design
    (2007) Rao, D.S.; Hebbar, H.S.; Komaraiah, M.
    Burnishing is used increasingly as a finishing operation which gives additional advantages such as increased hardness, fatigue strength, and wear resistance. Experimental work based on 34 factorial design was carried out to establish the effects of ball burnishing parameters on the surface hardness of high-strength low alloy steels (HSLA) dual-phase (DP) steel specimens. Statistical analysis of the results shows that the speed, feed, lubricant and ball diameter have significant effect on surface hardness.
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    Investigations on the effect of ball burnishing parameters on surface hardness and wear resistance of HSLA dual-phase steels
    (2008) Rao, D.S.; Hebbar, H.S.; Komaraiah, M.; Kempaiah, U.N.
    Surface finish has a vital influence on most functional properties of a component like fatigue life, wear resistance, corrosion resistance, etc. This has given birth to processes such as lapping, honing, burnishing, etc. Burnishing is a fine finishing operation involving the cold working plastic deformation of surface layers to enhance the surface integrity and the functional utility of a component. The present study has been carried out to establish the effect of burnishing parameters viz. feed rate, speed, force, ball diameter and lubricant on surface hardness, and wear resistance of HSLA dual-phase steel specimens. The result indicates that burnishing parameters have significant effect on the surface hardness and wear resistance.
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    Noise measurement in a mechanized opencast bauxite mine: A case study
    (Multi-Science Publishing Co. Ltd claims@sagepub.com, 2015) Tripathy, D.P.; Rao, D.S.
    Occupational noise is one of the most common pollutants in the mining sector. Prolonged exposure of miners to high levels of noise can cause noise induced hearing loss besides several non-auditory health effects. As these effects have a significant impact on people's health, it is essential to assess the noise exposure and to adopt ameliorative solutions. This work has been carried out to study the noise levels of different machines in a highly mechanized opencast bauxite mine of Odisha, India. A number of measurements have been carried out using an Extech 1/3 Octave band analyser and sound level meter to collect data where the miners are exposed to different tasks during the occupational process. Noise measurements were carried out at work places of 10 different machinery sources in the bauxite mine. The average noise levels generated from the different machines were compared with permissible exposure levels of workers as per OSHA guidelines. Further contour mapping was plotted to show the noise levels at each work place.
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    Comparative hot corrosion performance of APS and Detonation sprayed CoCrAlY, NiCoCrAlY and NiCr coatings on T91 boiler steel
    (Elsevier Ltd, 2021) Sundaresan, C.; Rajasekaran, B.; Varalakshmi, S.; Santhy, K.; Rao, D.S.; Govindarajan, G.
    Hot corrosion performance of Atmospheric Plasma Spray (APS) and Detonation spray (DSC) CoCrAlY, NiCoCrAlY, and NiCr coatings on T91 steel were investigated at 650 °C for 100 cycles under Na2SO4-K2SO4-Fe2O3 mixed salt deposit in ambient air. The hot corrosion resistance of DSC coatings was found to be superior to their APS counterparts. Chromia and spinel oxides provided excellent corrosion resistance while no ?-Al2O3 was observed. DSC NiCr and APS NiCoCrAlY offered the most and the least corrosion resistance, respectively. DFT calculation was performed to validate the thermodynamic stability of each oxide and identify the precise oxide formation. © 2021 Elsevier Ltd