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Pandey, Sunil
- Development of Mild Steel - B4C Surface Composite by Friction Stir Processing
Authors
1 Department of Mechanical Engineering, Indian Institute of Technology-Delhi, New Delhi – 110016, IN
Source
Indian Journal of Science and Technology, Vol 10, No 30 (2017), Pagination:Abstract
Objectives: Friction Stir Processing (FSP) is being attempted in this study to process the surface layer of mild steel and to explore the possibility of incorporating B4C particle into surface layer of mild steel to form surface composite by means of FSP technique. Methods: FSP with B4C particle was carried out on 5.0 mm mild steel and specimens 250 mm x 100 mm were processed in a single pass. The tool material used was tungsten carbide. Trial runs were carried out at different process parameters and the final parametric windows have been developed for getting the defect free surface. With optimized process parameters sound and defect free surface was made. Mechanical Properties were investigated through microstructure and hardness test. The micrographs and hardness graph have been presented and discussed in this paper. Findings: The Micrographs were taken using optical microscope at different location of the processed zone. There was distinct alteration in size and shape of the grains at different location of the processed area. Temperature in the stir zone is sufficient to convert the base material ferrite into austenite region of phase diagram. Since the recovery is slow in austenite, dynamic recrystallization occurs. The amount of deformation in friction stir processing is very large, therefore the critical condition for discontinuous dynamic recrystallization are met. This leads to very fine austenite grain formation. These fine recrystallized grains of austenite transform back into ferrite when the temperature falls down. Macro hardness test was also done using the Vickers hardness test. It was found that the average hardness has increased to more than three to four times in the processed zone as compared to the parent metal. Applications: Technology developed in this study can be effectively used in several areas like mining, mineral processing, aerospace and railway industry, where surface modification is a need to reduce various losses like wear and corrosion.Keywords
Boron Carbide (B4C), Friction Stir Processing (FSP), Metal Matrix Composites, Nano ParticlesFull Text
- Effects of Process Parameters on Weld Bead Penetration in SAW
Authors
1 Department of Mechanical Engineering, Indian Institute of Technology, Delhi, New Delhi 110016, IN
Source
Indian Welding Journal, Vol 34, No 4 (2001), Pagination: 24-32Abstract
A two-Level half fractional design is used to investigate and quantify the direct and interaction effects of four process parameters on weld bead penetration in SAW of mild steel.
Wire feed rate, open circuit voltage, welding speed and plate thickness were taken as the welding parameters to investigate the main and interaction effect on the weld bead penetration. The analysis indicated that of the four parameters investigated, only wire feed rate had the statistically significant main effect on weld penetration. It was also observed that wire feed rate & welding speed and open circuit voltage & plate thickness interact to affect the weld penetration. A model has been proposed for predicting the weld penetration. The adequacy of the model was tested by the use of analysis of variance technique and the significance of the coefficients was tested by the student’s ‘t’ test. The estimated and observed values of the bead penetration have been compared in a scatter diagram. The main and interaction effects of different parameters involved have been presented in graphical form.
Keywords
Submerged Arc Welding, Bead Geometry, Bead Penetration, Process Parameters, Modelling, Design of Experiments.
- Fusion Characteristics of an Al-Li Alloy in Pulsed-GMAW Process
Authors
1 Department of Science & Technology, New Delhi, IN
2 Indian Institute of Technology, New Delhi, IN
Source
Indian Welding Journal, Vol 34, No 2 (2001), Pagination: 29-36Abstract
Fusion Characteristics of High Strength Heat-treatable Aluminium-Lithium Alloy Plates, Using GMAW Process in Continuous and Pulsed Mode Were Studied. Burn-off Characteristic of the 1.6mm Diameter 2319-filler Wire in Continuous and Pulsed Mode. Including Relation Between Pulse Current and Pulse Duration for one Droplet Detachment Per Pulse was Determined.Keywords
Al-Li Alloy, Pulsed-GMAW, Bead Geometry, Aluminium Welding.- Surface Modifications Through Plasma Enhanced Shielded Metal Arc Welding Process (PESMAW)
Authors
1 Deptt. of Mechanical Engineering, Indian Institute of Technology Delhi, (IITD), New Delhi, IN
2 Dept. of Mechanical and Manufacturing Engineering, University of Calgary, Calgary, Alberta, CA
3 Dept. of Mechanical Engineering, Indian Institute of Technology Delhi, (IITD), New Delhi - 110016., IN
4 Dept. of Mechanical Engineering, Raazi Engineering College University of Raazi, Kermaanshah - 67139, IR
Source
Indian Welding Journal, Vol 36, No 2 (2003), Pagination: 27-30Abstract
Low alloyed steels are widely employed in the agricultural, transport and metal processing industries and are often treated to improve surface wear resistant properties. In this study, the surface of plain carbon steel is melted using a metal arc heat source and the surfaces are simultaneously alloyed using a metallic powder and nitrogen gas. This process is novel in that the nitrogen gas carries metallic powder through the electrode and into the plasma created between the tip of the electrode and substrate surface. The changes in wear characteristics of the modified surfaces are monitored using a pin-on-plate wear testing machine and micro-indentation hardness measurements as a function of depth from the surface. Preliminary results indicate a significant increase in wear resistance for surfaces alloyed with nitrogen and chromium powder compared to the untreated surfaces. These changes in wear properties are explained through changes in micro structural features within the solidified surface.Keywords
Surfacing, Surface Melting, Wear Resistance, Tribology of Steels, Surface Alloying, Hardness, Plain Carbon Steels, Plasma Enhanced Shielded Metal Arc Welding.- Welding Current in Submerged Arc Welding
Authors
1 Dept. of Mechanical Engineering, Indian Institute of Technology, Delhi, IN
2 Dept. of Mechanical Engineering, SBCET, Phirozpur, Punjab, IN
3 International Division, DST, New Delhi, IN
4 Dept. of Mechanical Engineering, Raazi Engineering College, Kermaanshah, IR
Source
Indian Welding Journal, Vol 36, No 1 (2003), Pagination: 16-22Abstract
A relationship between welding current and various welding parameters has been proposed. The relationship can be used to predict welding current and melting rates in submerged arc welding process. Two-level half-fractional factorial design was used to investigate and quantify the direct and interaction effects of four process parameters on welding current in SAW of mild steel.
Wire feed rate, open circuit voltage, welding speed and plate thickness were taken as the welding parameters to investigate the main and interaction effects on the welding current. A model has been proposed for predicting the welding current in submerged arc welding. The adequacy of the model was tested by the use of analysis of variance technique and the significance of the coefficients was tested by the student’s ‘t’ test. The estimated and observed values of the weakling current have been compared through a scatter diagram. The main and interaction effects of different parameters involved have been presented in graphical form.