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STUDY OF STRENGTH OF JOINT MADE BY TWO DIFFERENT ALLOYS BY MAG WELDING Vijay kumar *1 , Balwinder Singh 1 , Manoj Mittal 2 1) Depar tmen t of Mechan ical E ngin eering , Giani Zail Singh PTU Campus Bathinda , Punjab 2) Campus Director, Aryabhatta Group of Ins titutes, B arnala * Corresponding author: e-mail : [email protected] , contact -+9184272 03094 ABSTRACT In industrial applications various types of materials are used. Strength of weldment of two dissimilar materials especially alloys is major cause of interest among engineers. In this study steel P11 and P22 were welded using ER -70 - S6 wire electrode with Metal Active Gas welding process (MAG) using CO 2 as shielding gas. Strength of the joint was tested by impact test (Charpy test). It was found by the experiments performed on the specimen on impact testing machine, that the impact energy of welde d specimen was 49 Joule in Charpy impact test, whereas, the impact energy of parent metal P11 was 48 joule, whereas for P22, it was 64 Joule. The result of impact test s hows that the i mpact energy of weldment of P11 and P22 lies in between the impact energy of P11and P22. Key words: P11, P22, MAG welding, impact testing. 1. Intr oduc tion Welding is a process of joining similar or dissimilar materials. Welding is carried out by the use of heat or pressure or both and with or without added metal. There are many types of welding including Metal Arc, Tungsten arc, Submerged Arc, Resistance Butt, Flas h, Spot, Stitch , Stud and Pro jecti on. Iner t gas welding is faster than traditional welding methods. It can produce cleaner, longe r continuous welds. The main types of inert gas welding they are Tungsten Inert Gas Welding (TIG) a good description of which is gi ve n by by Pa ul o J Mo de ne si et al [1 ] an d METAL Inert Gas welding (MIG) and Metal Active Gas Welding (MAG) by William R. Oates et.al [2]. Alloy St ee l su ch as AS TM A3 35 P2 2, AS TM A335P11, contains chromium and molybdenum. This compos iti on del ive rs good we lda bil ity and high hardenability for the above stated alloys. Chromium provides improved oxidation and corrosion resistance. And the molybdenum increases strength at el ev at ed te mp erat ur e. Th e co mb inat ion of chromium and molybdenum also increases resistance to high temperature hydrogen attack and to creep. Chromi um and molybdenum st ee ls ar e used in va ri ous pr oduc ts fo rms acco rd ing to AS TM spe cif ic ations by J C Vail la nt et. al [4] . An investigation was carried to study the impact strength of two diffe re nt met al we lde d joi nt usi ng MAG we ldi ng compar ed wit h the imp act streng th bot h parent metal. This paper mainly deals with impact strength of welded joint compared with parent metal. 2. Materials And Methods The chemical composition of base metals as supplied by manufacturer and as tested by atomic emission spectroscopic analysis conducted at R & D centre for Bicycle and Sewing machine Ludhiana is presented in table-1 Table 1 Chemical composition of base metal Punjab Technical University, Jalandhar-Kapurthala Highway, Kapurthala, Punjab-144601 (INDIA) According to ASTM Standards Actual composition tested with atomic emission spectroscopic analysis Specification ASTM A 335/P11 ASTM A 335/P22 Specification ASTM A 335/P11 ASTM A 335/P22 C% 0.15MAX 0.15MAX C% 0.13 0.13 Mn% 0.30-0.60 0.30-0.60 Mn% 0.38 0.48 P% MAX 0.025 0.025 P% MAX 0.015 0.009 S% MAX 0.025 0.025 S% MAX 0.024 0.007 Si% 0.50-1.00 0.50MAX Si% 0.6 0.34 Cr% 1.00-1.50 1.90-2.60 Cr% 1.12 2.02 Mo% 0.44-0.65 0.87-1.13 Mo% 0.5 1.09 Fe % Balance Balance Fe % Balance Balance

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