Manufacturing Technology Today

A. Venkata Ramana ¹, Vijaya Singh ¹, Sriram Venkatesh ²

Affiliations
1 Light Alloys Casting Group, Defence Metallurgical Research Laboratory, Hyderabad, IN
2 Department of Mechanical Engineering, Osmania University, Hyderabad, IN

Abstract

In this article a freeform fabrication process based on laser melting of metal powders called Laser Engineered Net Shaping (LENS^TM) is discussed. Paper describes general features of the process and results of the experiments carried out to deposit stainless steel (SS316) test coupons. Finally the deposits have been characterized for their surface quality, hardness, tensile properties and microstructure, and efforts made to correlate them with specific power of the laser.

Keywords

Laser Melting, Layer Manufacturing, LENS Technology, Rapid Prototyping, Rapid Tooling.

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M. Sailender ¹, G. Chandra Mohan Reddy ², Sriram Venkatesh ³, P. V. R. Ravindra Reddy ¹

Affiliations
1 Dept. of Mechanical Engg., Chaitanya Bharathi Institute of Technology (CBIT), Gandipet, Hyderabad, IN
2 Mahatma Gandhi Institute of Technology, Gandipet, Hyderabad, IN
3 Dept. of Mechanical Engg, Osmania University College of Engg., Osmania University, Hyderabad, IN

Abstract

Submerged arc welding (SAW) is one of the important welding processes used for welding thick blocks. Since arc in this welding is submerged under the blanket of granular fusible flux, the bead cannot be seen while welding. Hence all parameters such as arc voltage, welding current, carrier speed, electrode feed rate, nozzle to plate distance and the gap between plates etc. are to be preset. So, the effect of the parameters on the bead geometry is to be found out for which a number of experiments are to be carried out. Hence, in this work, to reduce the number of experiments a screening test is initially conducted, using Taguchi Technique. Open circuit voltage (OCV), wire feed rate (WFR), carrier speed (CS) and nozzle to plate distance (NPD) are chosen as input parameters and the reinforcement, width and penetration of the weld bead are taken as output parameters. L8 orthogonal array is selected, the factors are assigned and experiments are carried out. Column effect method is used to find the most effective parameters on bead characteristics.

Keywords

Submerged Arc Welding, Weld Bead, Orthogonal Array (OA), Column Effect Method.

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