Reference no: EM133027950
MM5012 Welding Processes
- Answers to each question should not be more than 1500 to 2000 words. Use schematic figures wherever deems necessary.
- Evaluation method
- Diligence, analysis and technical correctness
- Structure and organisation, legibility of figures and writing style
- Application of appropriate references and sources while answering
1. Goldak J, Chakravarti A and Bibby M, A finite element model for welding heat sources, Metallurgical Transactions B, Vol. 15B, June 1984, pp. 299-305.
Explain step by step, using classical calculus, how the equations for calculating heat flux distribution in an arc (equations 16 and 17) are derived in the above mentioned article.
2. Amin S. Azar, A new heat source model for cold metal transfer (CMT) welding, Journal of Thermal and Analytical calorimetry, 121, 2015, 741-746.
Explain, using classical calculus, how the Goldak equations for heat flux distribution (question 1) in an arc is extended to controlled dip short circuiting transfer or cold metal transfer welding process in the above mentioned article. Both the journal articles are attached herewith.
3. You are required to introduce and control processes for welding of piping systems in a chemical process plant. The application consist of 75 mm OD x 3 mm wall thickness AISI 304 piping which is carrying warm dilute nitric acid. Recommend the process, operating mode and welding techniques which you believe are appropriate for achieving high joint integrity and optimum productivity. Explain your selection with reference to other process options.
4. Petroleum products are important by using transport vessels from source. These vessels bring the products to a tank terminal in a port and products are offloaded using high pressure pipelines (often in the order to 3000 psi or 340 bar). These pipelines are made using API (American Petroleum Institute) 5L grade steels. A typical composition of these steels is C-0.15, Mn-1 and Si-0.4 wt. %. Assume that you are working in a fabrication company which is given responsibility to install transportation pipelines from vessels to filling stations, what are the welding processes you would use to join these API grade pipes of 16 mm wall thickness. Given the fact that these pipelines are installed in highly corrosive environment, provide adequate corrosion protection strategy you would follow. Would you recommend any post weld heat treatment procedure as well? Justify your answer.