The Study of Multi-Stage Cold Forming Process for the Manufacture of Relief Valve Regulating Nuts

Cold forging is widely used in many industries. Multi-stage cold forming usually utilized fasteners. In this study, numerical simulation and experimental investigations were carried out on a five-stage cold-forming process for the manufacturing of low-carbon steel AISI 1010 relief valve regulating nuts. The through five stages included preparation centering backward extrusion, extrusion over die pin, upset, moving punch, piercing. formability workpiece was studied, such as effects force response, maximum force, effective stress strain distributions, metal flow patterns, strength. A comparison forces obtained experiment with results showed good agreement trend growth. For energy, fourth stage punch at upper face largest among stages. total from first to fifth numerically 440.9 kN experimentally 449.4 kN, meaning FE agreement. simulated distributions consistent tested hardness distributions. Highly compacted grain lines also resulted higher hardness. overall formed by increased 31% compared initial billet. stages, strain-hardening effect obvious. strength significantly forming.