Closed Die Hammer Forging of Inconel 718

Abstract

A method for the production of Inconel 718 (IN-718) hemispherical domes by closed die hammer forging is proposed. Different combination of operations employed for production are as follows: (i) preforging + final forging + air cooling, (ii) preforging + final forging + controlled cooling, (iii) direct forging + controlled cooling, and (iv) direct forging + air cooling. Last three combinations yielded a crack free hemispherical dome. The forged hemispherical domes were solution annealed at 980°C for 1 h and air cooled. The grain size of the domes at all locations was finer than ASTM No 4. Mechanical properties of the forged dome in solution treated and aged condition (STA) were better than feedstock used.