Jashanpreet Singh and Jatinder Pal Singh
This study aims to deal with development and performance analysis of high-velocity oxy-fuel (HVOF) thermally sprayed Mo2C-based WC-CoCr (tungsten carbine cobalt chrome) (Co-10…
Abstract
Purpose
This study aims to deal with development and performance analysis of high-velocity oxy-fuel (HVOF) thermally sprayed Mo2C-based WC-CoCr (tungsten carbine cobalt chrome) (Co-10% and Cr-4%) cermet coating deposited on the pump impeller steel 316 L.
Design/methodology/approach
In this work, a study was carried out by modifying the conventional WC-CoCr powder with a small addition of molybdenum carbide (Mo2C). Reinforcement was done by 1–4 wt.% addition of Mo2C feedstocks in WC-CoCr powder by using a jar ball mill process. The design of experiment was implemented for optimization of the percentage of Mo2C feedstock. L16 (4 × 4) orthogonal array was used to design the experiments for erosion output for the input parameters namely velocity, particle size, concentration and Mo2C proportion.
Findings
Results show that the Mo2C-based WC-CoCr coating provides better microhardness as compared to conventional WC-CoCr coating. The present study also reveals that the deposition of conventional WC-CoCr coating has improved the wear resistance of SS 316 L by 9.98%. However, the slurry erosion performance of conventional WC-CoCr coating was improved as 69.6% by the addition of 3% Mo2C.
Practical implications
WC-CoCr coatings are universally used for protecting the equipment and machinery from abrasion, erosion and corrosion. So, the 3% Mo2C-based WC-CoCr can be useful in power plants and various industries like mining, chemical, automobile, cementing and food processing industries.
Originality/value
A new HVOF coating has been developed by the addition of Mo2C feedstock in WC-CoCr powder (Co 10% and Cr 4%) and the percentage of Mo2C feedstock was optimized to improve the tribological behavior of WC-CoCr coating.
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The purpose of this study is to analyze the slurry erosion failure of Ni-20Cr (Ni-Cr2O3), Ni-20Al (Ni-Al2O3) and Al-20Ti (Al2O3-TiO2) coatings deposited on SS316L by the…
Abstract
Purpose
The purpose of this study is to analyze the slurry erosion failure of Ni-20Cr (Ni-Cr2O3), Ni-20Al (Ni-Al2O3) and Al-20Ti (Al2O3-TiO2) coatings deposited on SS316L by the high-velocity oxy-fuel process.
Design/methodology/approach
Slurry erosion experiments were conducted using a pot type erosion tester at different velocities 1.81, 2.71, 3.61 and 4.59 m/s for the time duration of 90-180 minutes. Fly ash and bottom ash were used as erodent media; the concentration of mass flux was taken as 30-60 wt. per cent. Artificial neural network (ANN) method was used to simulate the slurry erosion for thermally sprayed coatings.
Findings
Slurry erosion of coatings increases non-linearly with an increase in experimental durations, mass flux and velocity. Slurry erosion of Ni-20Cr and Ni-20Al layers was found to be maximum at 60° impingement angle, whereas 30° for SS316L and 45° for Al-20Ti coating. Slurry erosion performance of SS316L was improved by 2.56-3.19 times by depositing Ni-20Cr and Ni-20Al layers, whereas it improved 1.15-1.75 times by Al-20Ti coating. The slurry erosion SS316L was found almost 1.35 ± 1.28 times greater than that of the Ni-20Al coating, whereas it was to be 1.12 ± 1.36 times greater than Al-20Ti. Ni-20Al-coated SS316L showed a lower value of slurry erosion than Al-20Ti-coated SS316L.
Practical implications
Stainless Steel SS316L is widely used in hydraulic machinery (such as turbines, pumps, valves, fittings, etc.) of hydraulic and thermal power plants, chemical industry and marine industry. Therefore, the deposition of ductile and brittle coatings is a better option for their durable performance.
Originality/value
Erosion wear of Ni-20Cr, Ni-20Al and Al-20Ti coatings was successfully simulated by using an artificial neural network model by supplying experimental data as a target.
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The purpose of this paper is to carry out erosion wear investigation on high-velocity oxy-fuel (HVOF)-deposited 86WC-10Co4Cr and synergistic Ni/Chromia powder (i.e. 80Ni-20Cr2O3…
Abstract
Purpose
The purpose of this paper is to carry out erosion wear investigation on high-velocity oxy-fuel (HVOF)-deposited 86WC-10Co4Cr and synergistic Ni/Chromia powder (i.e. 80Ni-20Cr2O3) on AISI 316L.
Design/methodology/approach
Design of experiments-artificial neural network (DOE-ANN) methodology was adopted to calculate the erosion wear. Taguchi’s orthogonal array L16 (42) was used to perform set-of-erosion experiments followed by lower-the-better rule. The artificial neural network (ANN) model is used on erosion wear data obtained from the experiments.
Findings
Experimental results indicate that 86WC-10Co4Cr provided better erosion wear resistance as compared to Ni/Chromia. The erosion wear of 86WC-10Co4Cr and synergistic Ni/Chromia coatings increases with an increase in time duration, solid concentration and time. The magnitude of erosion generated by ashes was comparatively lower than sand. The arithmetic mean roughness (Ra) of finished AISI 316L, 86WC-10Co4Cr and Ni/Chromia coating was found as 0.46 ± 0.13, 6.50 ± 0.16 and 7.04 ± 0.23 µm, respectively. Surface microhardness of AISI 316L, 86WC-10Co4Cr and Ni/Chromia coating was found as 197 ± 18, 1,156 ± 18 and 1,021± 21 HV, respectively.
Practical implications
The present results can be useful for estimation of erosion wear in slurry pumps used in mining industry for the conveying of sand and in thermal power plants for the conveying of ashes to the dyke area.
Originality/value
The erosion wear of HVOF-sprayed 86WC-10Co4Cr and Synergistic Ni/Chromia powders was studied experimentally as well as predicted by the ANN model, and wear mechanisms are well discussed by scanning electron micrographs.
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Jashanpreet Singh, Satish Kumar and S.K. Mohapatra
This study/paper aims to investigate the erosion wear performance of Ni-based coatings [Ni-Cr-O and NiCrBSiFe-WC(Co)] under sand-water slurry conditions.
Abstract
Purpose
This study/paper aims to investigate the erosion wear performance of Ni-based coatings [Ni-Cr-O and NiCrBSiFe-WC(Co)] under sand-water slurry conditions.
Design/methodology/approach
A high-velocity oxy-fuel (HVOF) process was used to deposit the Ni-based coatings [Ni-Cr-O and NiCrBSiFe-WC(Co)] on the surface of stainless steel (SS 316L) substrate. A Ducom TR-41 erosion tester was used to conduct the tribological experiments on bare/HVOF coated SS 316L. The erosion wear experiments were carried out for different time durations (1.30-3.00 h) at different impact angles (0-60°) by running the pot tester at different rotational speeds (600-1,500 rev/min). The solid concentration of sand slurry was taken in the range of 30-60 Wt.%. The surface roughness of Ni-based coated surfaces was also measured along the transverse length of the specimens.
Findings
Results show the arithmetic mean roughness (Ra) values of Ni-Cr-O and NiCrBSiFe-WC coated SS-316L were 7.04 and 6.67 µm, respectively. The erosion wear SS-316L was almost 3.5 ± 1.5 times greater than that of the NiCrBSiFe-WC coatings. NiBCrSi-WC(Co) sprayed SS-316L showed lower erosion wear than Ni-Cr-O sprayed SS-316L. Microscopically, the eroded Ni-Cr-O coating underwent plowing, microcutting and craters. Ni-Cr-O coating have shown the ductile nature of erosion wear mechanism. NiBCrSi-WC(Co) surface underwent craters, plowing, carbide/boride pullout, fractures and intact. Erosion wear mechanisms on the eroded surface of NiBCrSi-WC(Co) were neither purely ductile nor brittle.
Practical implications
It is a useful technique to estimate the erosion wear of hydraulic machinery coated with Ni-based coatings imposed under mining conditions.
Originality/value
The erosion wear performance of HVOF-sprayed Ni-Cr-O and NiCrBSiFe-WC(Co) powders was investigated through extensive experimentation, and the results are well supported by scanning electron micrographs and 3D topology.
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Jagdeep Singh, Harwinder Singh, Amandeep Singh and Jashanpreet Singh
The purpose of this paper is to cover the significance of lean thinking using value stream mapping and six sigma methodology in managing industrial operations.
Abstract
Purpose
The purpose of this paper is to cover the significance of lean thinking using value stream mapping and six sigma methodology in managing industrial operations.
Design/methodology/approach
Lean manufacturing is an efficient approach for identifying and eliminating waste through a continuous improvement via flow of the product/service at the pull of customer in chase of exactness. This study has been carried out in a manufacturing unit of Northern India that was suffering from high production lead time and work in progress (WIP) inventory.
Findings
The current state and future state maps for the critical product have been prepared. On comparison of both current and future state maps, it was observed that lead time has been reduced by 14.88 percent, processing time by 14.71 percent and wastage of material movement by 37.97 percent. As proposed in model, the WIP inventories have been reduced by 17.76 percent and workforce by 17.64 percent. Further it would lead to the profit of Rs161,800 per annum. Six sigma projects have been carried out to reduce rejections of the critical product P-19 under study. The total length of the product was undersize of the critical product. Root cause analysis technique has been used through strategic DMAIC implementation. Results of investigation demonstrated net savings of rupees 145,560 annually.
Originality/value
The paper demonstrates the practical application of lean thinking, showing how it can bring real breakthroughs in saving cost in the manufacturing industry.