Rajnish Garg

EFFECT OF INTERMETALLIC PHASES ON CORROSION BEHAVIOR AND MECHANICAL PROPERTIES OF DUPLEX STAINLESS STEEL AND SUPER-DUPLEX STAINLESS STEEL

Duplex Stainless Steels (DSS) and Super Duplex Stainless Steel (SDSS) have excellent integration of mechanical and corrosion properties. However, the formation of intermetallic phases is a major problem in their usage. The mechanical and corrosion properties are deteriorated due to the presence of intermetallic phases. These phases are induced during welding, prolonged exposure to high temperatures, and improper heat treatments. The main emphasis of this review article is on intermetallic phases and their effects on corrosion and mechanical properties. First the effect of various alloying elements on DSS and SDSS has been discussed followed by formation of various intermetallic phases. The intermetallic phases affect impact toughness and corrosion resistance significantly. Their deleterious effect on weldments has also been reviewed.

Tribological behavior of pongamia oil as a lubricant additive

ABSTRACT This study assesses the friction and wear characteristics of a pongamia oil-contaminated bio-lubricant by using a pin-on-disc tribometer. To formulate the bio-lubricants, pongamia oil was blended in the ratios of 15, 30, and 50% by volume with the base lubricant SAE 20 W 40. Tribological characteristics of these blends were obtained at 1.3 and 2.5 m/s sliding velocity and the load was 150 N. Experimental results showed that the lubrication regime that occurred during the test was boundary lubrication while the main wear mechanisms were abrasive and the adhesive wear. During testing, the lowest wear was found with the addition of 15% pongamia oil, and above this contamination, the wear rate was increased considerably. With an increase in load, the viscosity of all the bio-lubricants increases and meets the International Standard Organization (ISO) VG 100 requirement at 40°C except PB 50. The addition of pongamia oil in the base lubricant acted as a very good lubricant additive which reduced the friction and wear scar diameter during the test. It has been concluded that the PB 15 can act as an alternative lubricant to increase the mechanical efficiency and contribute to reduction of dependence on the petroleum-based products.

Experimental study of the performance and emission of diesel engine fueled with blends of diesel-ethanol as an alternative fuel.

Evaluation of performance and emission was performed on a 3.7-kW, single-cylinder, four-stroke variable compression ratio diesel engine at a rated speed of 1500 rpm. The load ranges (0–0.7 kW, 1.2–2.3 kW, and 2.8–3.5 kW) are indicated as low, medium, and high loads respectively. Different blends of diesel and ethanol were prepared for the study on a volume/volume basis. The blends containing 5%, 10%, 15%, and 20% ethanol were fuel D95E5B0, D90E10B0, D70E15B15, and D60E20B20 respectively. Diesel–ethanol blends were D95E5B0 and D90E10B0, whereas diesel–ethanol–biodiesel blends were D70E15B15 and D60E20B20. The outcomes of the study showed that the brake thermal efficiency slightly decreased with increase in ethanol, the brake-specific fuel consumption increased with increase in ethanol, and the exhaust gas temperature increased for higher load and higher ethanol content in the blend. Oxides of nitrogen, carbon dioxide, hydrocarbon, and carbon monoxide decreased while smoke reduced drastically with a higher percentage of ethanol in the blend.

A review of biofuel generated contamination, engine oil degradation and engine wear

ABSTRACT Engine oil contamination, degradation and wear of engine components occurs mainly due to fuel dilution, oxidation and blow-by. This contamination accelerates the wear of engine components and also decreases the useful service life and performance of engine oil. Failure of engine oil can cause engine component failure. The three major contaminants which initiate engine oil degradation and engine component wear are soot, water and particles. Soot contamination in lubricating oil is responsible for oil thickening and engine wear. Water emulsifies the oil and the wear debris generated further enhance the wear rate as three body abrasive process. This paper reveals the role of biofuels in engine oil degradation in terms of contamination, fuel dilution, oxidation and blow-by and wear. This paper provides a platform to understand the tribological relationship between lubricating oil and engine components.

Aspects of Non-edible Vegetable Oil-Based Bio-lubricants in the Automotive Sector

Abstract Lubricants act as anti-friction media and facilitate smooth operations, maintain machine reliability and lead to reduction in the risk of frequent failures. Around the globe, petroleum-based reserves are depleting which results in price hike, creating concern about environmental pollution. The researchers are focusing on developing and using an eco-friendly lubricant derived from renewable resources. Non-edible vegetable oil-based bio-lubricants are eco-friendly due to their biodegradability, non-toxicity and net zero greenhouse gas emission. This study presents the potential of using non-edible vegetable-based bio-lubricants in the automotive sector. The first part of the study discusses about the resources, properties, as well as advantages and application of the bio-lubricants. In the second part of this paper, the potential of non-edible oil-based bio-lubricants as alternatives are discussed. The final part includes the description about the global lubricant market and prospects for the future. Non-edible vegetable oil-based bio-lubricants have enhanced lubricity, high viscosity, good anti-wear property, high viscosity index, increased equipment service life, high load carrying ability, low evaporation rates and low emission of metal traces into the atmosphere.

Effect of load on friction and wear characteristics of Jatropha oil bio-lubricants

We, the Editor and Publishers of Biofuels have retracted the following article: Yashvir Singh, Rajnish Garg & Suresh Kumar (2017) Effect of load on friction and wear characteristics of Jatropha oil bio-lubricants, Biofuels, 8:1, 125-133, DOI: 10.1080/17597269.2016.1215065 This article has been retracted due to image duplication and manipulation. An investigation was conducted, and “worn surface image” panels in Figure 8 were found to be published in two other articles. What the images are said to represent varies by article and the authors have not been able to provide the original images. Thus, the conclusions of the present article cannot be verified. The two other articles containing “worn surface image” panels from Figure 8 include: Yashvir Singh, Amneesh Singla, Anshul Kumar Singh & Avani Kumar Upadhyay (2018) Tribological characterization of Pongamia pinnata oil blended bio-lubricant, Biofuels, 9:4, 523-530, DOI: 10.1080/17597269.2017.1292017 (see Figure 6(c) and 6(d), which are resized (stretched) versions of Figure 8(a) 150 N and 8(d) 150 N, respectively) Yashvir Singh, Rajnish Garg & Ajay Kumar (2016) Tribological behavior of pongamia oil as a lubricant additive, Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 38:16, 2406-2412, DOI: 10.1080/15567036.2015.1089341 (see Figure 7(c) and 7(d), which are identical to those in reference 1, above, and correspond with the retracted articles images in the same way) The authors do not agree with the retraction. We have been informed in our decision-making by our policy on publishing ethics and integrity and the COPE guidelines on retractions. The retracted article will remain online to maintain the scholarly record, but it will be digitally watermarked on each page as “Retracted”.

Condition Assessment Study of A-286 Alloy Gas Turbine Wheel

Life extension programs for rotating and nonrotating gas turbine components are popular and widely practiced in the industry. It is often possible to extend the life of the component beyond the design life through life assessment studies. The life assessment study generally includes a combination of nondestructive and destructive tests. Considering the life assessment approach, a Frame 5002 unit gas turbine wheel was examined nondestructively. The material of the turbine wheel is A-286, which is an iron-based super alloy. This turbine wheel has accumulated more than 200,000 service hours. The objective for nondestructive testing of this wheel was to check for any material degradation and any surface cracking in order to ensure extended service hours. The nondestructive tests included eddy current test, ultrasonic flaw detection, replica metallography, and portable hardness test. As such, no significant abnormalities were detected in the nondestructive tests performed. The replica metallography revealed excessive carbide precipitation. It was recommended to retire the turbine wheel from service. The significant test result findings of replica metallography are presented and discussed in this paper.

A Study on Ni-P and Ni-P-ZnO Composite Coatings Developed by Electroless Technique

A new processing concept has been developed to produce nano structured metal matrix composite coatings. Electroless coatings of Ni-P and composite Ni-P-ZnO were developed by co-deposition process on mild steel substrates. Ni-P-ZnO coatings were prepared using conventional route i.e., ZnO particles of ~ 20 μm with average diameter were added to the bath (900C, pH ~9.0) and kept in suspension by stirring. Uniform and grayish bright coatings were observed. The coatings were heat treated at 400°C for 1h in argon atmosphere to attain crystalline nature of coating. The as-synthesized and heat treated Ni-P and composite Ni-P-ZnO coatings were characterized by XRD, FESEM and AFM.

Wear Properties of A356/Al2O3 Metal Matrix Composites Produced by Insitu Squeeze Casting Techniques

Tribological behaviour of vanadium pentoxide reinforced A356 composite prepared by reacting oxide particles in different weight percentage with A356. The effect of oxide powder addition on tribological properties of produced composite was investigated. Sliding velocity, sliding distance, normal load and mass fraction of V2O5 particles were among the factors considered in the study. The influence of these factors on the tribological behaviour of the fabricated composite was analysed experimentally and discussed with surface morphologies. A notable augmentation in terms of hardness has been recorded which in turn enhanced and improved the tribological properties of prepared composites in comparison with the base alloy i.e. A356. Refinement of in situ V2O5 particles can be attributed the formation of hardened precipitates which in turn resulted in increase in the hardness of the composites.

Comparative tribological investigation on EN31 with pongamia and jatropha as lubricant additives

ABSTRACT The friction and wear experiments on EN31 are carried out with blends of pongamia (Pongamia pinnata) and jatropha (Jatropha curcas) with mineral oil and also conventional petroleum oil using a pin-on-disc tribometer at various loads and sliding distances. A significant drop is observed with 15% addition of pongamia and jatropha in comparison to mineral oil, for the complete tested sliding distances and loads, leading to the potential use of vegetable oil in tribological applications. To understand the lubrication regimes, a Stribeck curve is also drawn. Both pongamia and jatropha having 15% addition showed a reduction in the boundary lubrication regimes, contributing to a former start of full film lubrication.