Investigation of hot forming properties of a hand tool and its die in the hot forging process

Forging is one of the most practical methods for easily shaping metals through patterns and tools. The process involves applying force to the metal object through hammering or pressing. It is one of the oldest and most useful metal shaping methods, dating back several thousand years. The forging process produces products that are highly structurally reliable and have a high strength-to-weight ratio, making it one of the most suitable manufacturing processes to consider for producing high-strength and long-lasting products. To reduce the cost of the forging process, the method should be designed to utilize the best parameters that can produce higher-quality (high strength and high reliability) products compared to other production methods. However, creating a process for new product design is not simple. Producing a satisfactory product and establishing the process requires a lot of trial and error. The empirical trial and error method is commonly used for the forging process but is time- consuming and costly. With the presence of high-efficiency numerical techniques such as the Finite Element Method (FEM) or Finite Volume Method (FVM), computer simulations are used to test the performance of manufacturing processes. Computer simulation was introduced as a possible alternative in the early 1980s with the development of analysis techniques like FVM or FEM. Many successful attempts have been made to optimize and examine die design and produce higher- quality forged parts. Various techniques such as Finite Element Method (FEM) and Finite Volume Method (FVM) have been adopted in the literature. Hot forging is a promising technique for optimal material utilization and the production of components with better mechanical properties. The die used in hot shaping processes is typically subjected to high thermomechanical loads, so the service life of dies is primarily limited by wear and plastic deformation. The service life is related to the cost of re-production and the economy of hot forging processes. Therefore, the primary task of research in the hot forging industry is to improve the service life of forging dies. The die service life is determined by the number of forgings produced in terms of dimensional tolerance, or the service time the die can withstand without failure. Forging companies often use a trial-and-error method during the design process. Additionally, critical issues such as material loss due to incomplete filling of the die and the formation of flash are important considerations. However, the forging industry is becoming increasingly competitive in improving the final product quality while reducing production costs. In this study, the hot forging process actually applied at Izeltas A.S. was simulated one-to-one using commercial Finite Volume Method (FVM) software. The results, such as temperature changes, stress-strain values occurring in the die and the part, and wear depths in the die, were experimentally verified through metallographic and mechanical examinations of samples taken from the actually produced product. After the validation of the simulation results, critical parameters such as die material, die hardness, die preheating temperature, template temperature, and impact percentages were altered to improve the current hot forging process. The effect of these variables was determined using a commercial FVM analysis program. The operations were carried out at Izeltas. The compatibility of the experimental and simulation studies on the hand tool showed that the method followed with the help of FVM for the die is highly reliable, and satisfactory results can be obtained for future studies.