There are several techniques you can use for steel fabrication. They include broaching, machining, stamping, casting and shearing. Casting is an age-old method that dates back several decades. In this technique, the fabricator takes molten steel and pours into a mould with a specific shape. They will leave the molten material in the mould to cool and solidify to retain the proper shape. The simple and straightforward approach makes casting a flexible steel fabrication technique. It is ideal for turning steel into complex shapes provided you have a suitable mould to execute the job. Here is a detailed discussion on casting when fabricating steel:
Types of Casting
Over the years, there have been many changes in the casting method for steel fabrication. The method falls into different categories including:
1. Sand casting: Sand casting requires synthetic or natural sand as a refractory material. In technical terms, the fabricators refer to the sand as silica. Fabricators select the sand carefully to ensure that they can pack it densely. The particles also need to be large enough so that gasses any gases generated during the moulding process can leave through the pores. Usually, the equipment has a funnel that plays the role of a pouring cap to allow the metal to flow into the cope (top part) and the drag (bottom part). Steel parts produced by this method have a poor finish but high tolerance to harmful elements.
2. Shell-mould casting: Steel components made by shell-mould casting yield better tolerance and surface qualities than those made using the sand casting method. The process involves a two-piece pattern made of steel or aluminium heated to high temperature and coated with a suitable lubricant. Each of the half patterns is covered with a thermoset epoxy resin or mixture. A special binder glues the sand and the patterns together to form the mould. When the steel solidifies, the shell breaks to form the part you are fabricating.
The Benefits of Casting
Casting has several advantages over other steel fabrication techniques. First, it allows you to fabricate steels with different carbon contents provided you can melt them and pour them into the mould. Secondly, it is the easiest way of fabricating steel into components with complex shapes. The molten material takes the form of the mould, meaning you can get whatever you want if you have the mould. Lastly, you can change your mould desirably to get the desired dimensional accuracy of the components you are fabricating.