Question

For ferrous alloys, the breaking of mould should be done at a temperature_____

(a) 780 ⁰C

(b) 850 ⁰C

(c) above 700 ⁰C

(d) below 700 ⁰C

This question was addressed to me in an interview.

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

Answer 1

Correct answer is (d) below 700 ⁰C

Explanation: Ideally, the moulds should be broken at a temperature when no transformation occurs. For ferrous alloys, the breaking should be done at a temperature below 700 ⁰C. If the castings are fragile and thin, they should be removed at a temperature as low as 400 ⁰C to avoid any deformation to the metal castings at the time of breaking of mould.