DESIGN IN THE MANUFACTURE OF THE CRUSHER JAW USING HADFIELD STEEL PART TWO: MOULD MAKING, MELTING, CASTING AND HEAT TREATMENT
Authors: Sadjere E.G, *Ariavie G.O, Efe-Ononeme O.E
In a previous study of the design and production of the crusher jaw, the gating and risering necessary for the proper filling and feeding of the casting to eliminate casting defects like shut-run, cold-shut and porosity were designed. This current study produced the complimentary processes including mould making, melting, casting and heat treatment that were required to mitigate some more casting defects and achieve the needed properties. Moulding was made of basic sand of Chromite from a pattern made form Sapele Walnut with 2% pattern maker’s shrinkage. The melt was made of graded scraps of mild steel, charged with Ferro-alloys: Ferro-manganese and Ferro-silicon; and cast from a bottom-pour ladle. The heat treatment was to achieve retention of austenite by quenching after austenitizing at temperatures of 950oC, that is, above Acem for steel of 1.25% Carbon content and soaking until full austenite transformation was achieved. All processes were successfully carried out and the casting produced worked satisfactorily for more than six months.
Affiliations: Department of Mechanical Engineering, Faculty of Engineering, University of Benin, PMB 1154, Benin City, Nigeria.
Keywords: Pattern, Mould, Melting, Casting, Heat Treatment
Published date: 2017/12/29