Archive > Casting Technology > May-August 2010

CASTING TECHNOLOGY May - August 2010 Issue

A Complete Global Publication on Ferrous and Non-Ferrous Foundries

Special Feature

Effects of Core Materials on Solidification Time and Pattern in Steel Castings

NEWS CORNER

• Frederick A. “Fritz” Henderson joins Sunoco to lead SunCoke Energy

  Sunoco, Inc. has announced that Frederick A. “Fritz” Henderson has joined the company as a senior vice president to help prepare for the previously announced separation of SunCoke Energy from Sunoco.

• Indian aluminium manufacturer oppose spot pricing of alumina

  India’s aluminium manufacturers are against the proposal to shift to spot pricing for alumina due to slow Chinese demand and sharp price fluctuations. They prefer the present method of price discovery through long-term contracts.

TECHNOLOGY FOCUS

• Copper and Copper Alloys - Newer Materials and Processes†

  Copper and copper alloys are versatile in their application and are economical for the manufacture of engineering components. There is a copper alloy for mundane applications like plumbing and also for sophisticated electronics uses and a suitable method for making them.
  The review highlights some details of newer materials, their applications and innovative processes which enhance strength, quality and saleable yields. New materials include high conductivity Cu-Fe-P-Zr, Copper MMC, Cu-Mg-Fe etc.; spinodal alloys, heat-treated aluminium bronzes, high strength manganese bronzes and lead-free bronzes.

EDITOR'S COMMENT

India's foundry industry holds opportunities & new challenges
India's foundry industry is now the fourth largest in the world and booming at a rapid pace in shaping the country's economy. India has improved its casting production by more than 100 percent since the year 2002. No other nation has achieved that growth during that period.

REFRACTORY

Monolithic Refractories in Casting House of Blast Furnace

Trough system of a blast furnace (BF), consisting of main trough, iron runner, slag runner, skimmer and tilting runner, serves the function of providing channels for the hot metal and slag flowing out of the BF to the transporter. They are among the most important facilities of iron-making as their durability affects production circulation. As pointed out in Fig. 1, large capacity and long campaign life have been the trend of modern blast furnace. Higher blast temperature, higher tapping temperature and higher utilization factor have imposed much tougher working conditions on BF troughs and runners, principally because of higher temperature of hot metal and larger flow, which sets more stringent requirements on refractories not only in performance but also in installation.

SPECIAL COVERAGE

• Effect of Core Materials on Solidification Time and Pattern in Steel Castings†

  Castings are often required to have holes and recesses of various sizes and shapes. These impressions in castings can be obtained by using cores. In the present work, a numerical study of heat transfer during the solidification of steel casting with core has been presented. A conjugate conduction based finite element heat transfer analysis of metal, mould and core with interfacial air gap has been performed. The heat transfer through the air gap has been modelled using the coincident node technique. Effect of core materials on solidification times and patterns of square shaped steel castings has been studied. The solidification time and sequence of solidification pattern is different when zircon is used as core material in comparison to silica.

COMPANY REPORT

Sunoco reports results of second quarter 2010

Sunoco, Inc. has reported net income attributable to Sunoco shareholders of $145 million ($1.20 per share diluted) for the second quarter of 2010 versus a net loss attributable to Sunoco shareholders of $55 million ($.47 per share diluted) for the second quarter of 2009. Excluding special items, Sunoco had income for the 2010 second quarter of $158 million ($1.31 per share diluted) compared to 2009 second quarter loss of $31 million ($.27 per share diluted).

TECHNOLOGY/PROCESS REVIEW

• Influence of Microstructure and Turning Inserts on Machinability and Surface Characteristics of Hypereutectic Al-Si Cast Alloys

  The microstructures, machinability and surface characteristics of hypereutectic Al-Si cast alloys were studied after various melt treatments like refinement and modification. Results indicate that combined refined and modified Al-17Si-4.5Cu cast alloys have microstructures consisting of uniformly distributed primary silicon, interdendritic network of fine eutectic Al-Silicon and fine CuAl2 particles in the interdendritic region. These alloys exhibited better machinability and surface finish in the cast condition as compared with the same alloy subjected to only refinement or modification. Performances of the turning inserts (Un-coated, PVD and Polished CVD diamond-coated) were evaluated in machining hypereutectic Al-Si cast alloys under dry environment using a lathe. The Polished CVD diamond-coated insert outperformed the Un-coated or PVD-coated cutting inserts which suffered from sizeable edge buildup leading to higher cutting force and poor surface finish. The Polished CVD diamond-coated insert shows a very small steady wear without flaking of the diamond film during cutting. This paper attempts to investigate the influence of refinement, modification and combined action of both on the microstrutural changes in the hypereutectic Al-Si cast alloys and their machinability and surface finish when different turning inserts used.

• Role of Process Control in Aluminium Casting Foundry for Global Business

  The true enlightenment came from measuring the stability of the process conducted to carry out series production. Relationship between stability of process with rejection percentage could then be defined and established. The more stable the process, the lesser is the rejection. Conversely, it was also determined that the more the deviation from established process, higher the rejection.

CASE STUDY

Computer-Aided Simulation and Optimisation of Casting - A Case Study

Casting is the fundamental process of manufacturing. In this process, most important factor is to get the shrinkage-free product which needs proper design of runner, riser and its neck. Though these elements are not the part of the actual casting but they are essential components of a casting. The sizes of these elements are to be optimised properly to get maximum casting yield as this reduces the re-melting cost of the component and also reduces energy requirement by a huge amount because of lower hot metal. In this study, a cast iron pan has been identified which is one of the oldest components of Howrah cluster. It is expected that this work will be of great importance to the small-scale entrepreneurs and to the professionals who are working in this area.