Study of Failure Modes Affecting a Crimped Nut Related to Forging Process

• Published in: Journal of failure analysis and prevention Vol. 12; no. 2; pp. 130 - 138
• Main Authors: HENTATI, N, MAKNI, A, ELLEUCH, R
• Format: Journal Article
• Language: English
• Published: Materials Park, OH ASM International 01.04.2012; Springer Nature B.V
• Subjects: Applied sciences; Brasses; Cold forging; Exact sciences and technology; Folding; Forging; Fractures; Heat treatment; Leaded brasses; Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; Metals. Metallurgy; Reproduction; Stamping; Bolted joint; Forging process; Failure mode; Heat treatment; Chemical analysis; Brass; Cracking; Laboratory scale; Copper base alloys; Nut; Crimped nut; Forging; Crimping; Manufacturing process; Oxidation; Microstructure; Zinc alloy; Fracture mode
• ISSN: 1547-7029; 1864-1245
• DOI: 10.1007/s11668-012-9549-1

In this current study, the problems caused by hot and cold forging--the two successive manufacturing process of a crimped nut--were investigated and resolved. The forged material is a leaded brass (CuZn39Pb2). Concerning the problem faced during hot forging (stamping), we chose a methodology based on the reproduction of industrial phenomena in laboratory scale. The study of this problem was conducted by micrographic and chemical analyses. For cold forging (crimping), a mechanical and microstructural characterization of the brass was performed in various conditions of heat treatment and shaping. Two items were proven in this study: (1) the use of graphite reduced the oxidation of the brass which was heated at the forging temperature to quarter; and (2) the heat treatment and annealing at 300°C avoided cracking during cold forging.[PUBLICATION ABSTRACT]