Question

Which of the following types of mould will have the longest period of cooling time for the same castings?

(a) Green sand mould of simple shape and size

(b) Dry sand mould of simple shape and size

(c) Dry sand mould of complex shape and size

(d) Green sand mould of complex shape and size

I have been asked this question in semester exam.

My query is from Casting Cleaning in portion Pouring – Gating Design, Melting Furnaces, Melting and Casting Quality of Casting-Forming-Welding I

Answer 1

Right choice is (c) Dry sand mould of complex shape and size

Best explanation: Dry sand mould of complex shape and size will have the longest period of cooling time, it is around 18-30 hours for 3000-5000 kg of mass of castings. The cooling time also depends upon the mass of the castings, for the same sand mould the cooling time can be reduced up to 50% if the mass of castings comes in the range of 1000-3000 kg.