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Metal Casting Technologies : September 2007
www.metals.rala.com.au 32 2007 OVERVIEW AsianFoundry INDIA By Dr. P. C. Maity, Professor, Foundry Technology Department, National Institute of Foundry & Forge Technology The growth of Indian foundry industries is being fuelled by the current rapid economic growth, rise in export opportunities and bright prospect in steel, automotive, and machine tool sectors. The National Steel Policy 2005 demands the indigenous steel production of 100 mT by 2020 in comparison to the current production of 44 mT per year. Increase in steel production to such an extent would require more tonnage of castings such as slag ladles, ingot molds and other components of blast furnaces. The growth rate of automotive industry was 16% in 2004-05 and 15% in 2005-06. Hence the demand of automotive castings such as cylinder head and block, manifolds, suspension and transmission components etc. is expected to grow rapidly. Both the GDP and Indian foundry industries' growth rate are expected to be close to 8%. The production of castings in India has increased from 3.15 mT in 2001 to nearly 6.15 mT in 2005. As predicted by various government agencies, the production of castings is expected to reach 10 mT by 2010. The export of industrial castings was 0.4 mT and that of sanitary castings was 0.65 mT in 2005-06. Molding / core making practices and usage of melting furnaces in Indian foundries are related to the annual production of various types of foundries. Based on available data, a number of foundries have been surveyed to assess the trend in molding / core making practices and melting furnace usage (Table - 1). Molding Majority of the castings are being produced in sand molds with different types of binders, rest are being produced by die casting, centrifugal and investment casting routes. In sand castings, green sand and dry sand molds are used by most of the foundries (Table - 2). Molds with higher cost binders, i.e. sodium silicate/CO2 and different types of resins are used increasingly by medium and large scale foundries. A few foundries are using molasses as a binder in molding sand. The analysis of available data leads to the following conclusions: ■ Small scale foundries are using green sand / dry sand molds, as the cost of binder, i.e. clay is less and iron castings produced satisfactorily in these type of molds are the major product of this sector. ■ There is steady growth in use of sodium silicate / CO2 bonded sand probably due to increasing awareness and its ability to produce comparatively more dimensionally accurate castings. ■ Medium and large scale sectors have preferred resin binders, not small scale foundries. The same is true for high pressure molding line. ■ Gravity die casting and pressure die castings have grown in numbers steadily, whereas the trend in case of centrifugal casting and investment casting is irregular. Since the application of non-ferrous castings, especially aluminum alloy castings, are increasing in recent years, the number of gravity die casting and pressure die casting foundries that produces these castings, are also increasing. Source: Indian Foundry Directory-1997, 2001 and 2005. All data in the above Tables are based on availability and are indicative only TYPE OF FOUNDRY NO. OF FOUNDRIES IN THE YEAR 1997 NO. OF FOUNDRIES IN THE YEAR 2001 NO. OF FOUNDRIES IN THE YEAR 2005 Small, Up to 1000 T annual production 574 740 706 Medium,1000 T to 5000 T annual production 306 410 445 Large, More than 5000 T annual production 98 160 187 TYPE OF MOULDING /CASTING SMALL, UP TO 1000 TONS ANNUAL PRODUCTION MEDIUM, 1000 TO 5000 TONS ANNUAL PRODUCTION LARGE, MORE THAN 5000 TONS ANNUAL PRODUCTION 1997 2001 2005 1997 2001 2005 1997 2001 2005 Green Sand 400 556 473 234 321 338 88 122 132 Dry Sand 156 200 81 60 116 54 22 32 15 CO2 Mold 56 65 125 52 75 124 18 25 41 No Bake Mold 108 110 101 92 130 147 36 60 58 Shell Mold 76 102 108 62 81 109 18 35 47 Molasses Mold 12 30 19 16 9 19 - 2 11 High Pressure Mold 2 1 6 4 8 24 4 25 25 Gravity Die Casting 64 101 120 10 13 38 6 10 21 Pressure Die Casting 34 46 73 - 8 27 4 9 14 Centrifugal Casting 14 16 31 8 20 15 16 11 23 Investment Casting 22 25 28 - 4 3 - 3 5 Table 2. Trends in use of different types of Molding / casting routes Table 1. Total number of foundries surveyed for molding / core making and melting furnaces