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Introduction
Published in Xin Min Lai, Ming Wang Fu, Lin Fa Peng, Sheet Metal Meso- and Microforming and Their Industrial Applications, 2018
Xin Min Lai, Ming Wang Fu, Lin Fa Peng
Metal forming is an efficient manufacturing process for making net shape or near-net shape parts and components by employing the plasticity of materials to deform the materials. This traditional metal-forming process was a common practice for making simple tools a few thousand years ago. The blacksmith in ancient times used tools such as a hammer and an anvil to deform heated metals. Nowadays, this process offers many unique and attractive advantages, such as high productivity, low production cost, excellent material utilization, superior mechanical properties, and complex geometries of the deformed parts and components using the modern forming equipment [2]. With the ever-increasing costs of materials, energy, and manpower, and increasingly strict statutory regulations arising from environment-friendly and sustainable development, this conventional manufacturing technology is now facing more new challenges in terms of productivity, cost, and quality.
Metals I: Metals Preparation and Manufacturing
Published in Ronald Scott, of Industrial Hygiene, 2018
Modern industrial forging is an update of the blacksmith tradition. Blacksmiths heated metal and hammered it into horseshoes, swords, or other objects. There are a number of variations of the forging technique; this discussion does not attempt to cover all bases. Instead the focus is placed on a few typical operations. Room temperature forging is called cold forging. More often metal is first heated to make deformation into the desired shape easier (Table 18.1). Deformation involves hammering or squeezing a piece of metal to shape by forcing it into a die with one or more blows of a press, by rolling a length of material into a desired cross-section between grooved rollers, or by extruding through a die to form wire or rods of a desired cross-sectional shape.
Use of Conventional Manufacturing Techniques for Materials
Published in T. S. Srivatsan, T. S. Sudarshan, K. Manigandan, Manufacturing Techniques for Materials, 2018
T. S. Srivatsan, K. Manigandan, T. S. Sudarshan
Often, simple forging operations are performed using a heavy hammer and an anvil, as has been traditionally practiced by blacksmiths. However, currently most forgings necessitate the need for a set of dies and powered hammers. When the forging operation is carried out at room temperature (25°C), it is referred to in industry circles as cold forging (Schey 2000). When carried out at an elevated temperature, it is known, or referred to, as warm forging or hot forging, depending on the homologous temperature. Due to high strength of the chosen workpiece material, the technique or operation of cold forging often necessitates the requirement for higher forces. Further, the chosen material must possess adequate ductility at room temperature (25°C) to be able to undergo the required deformation without cracking. The cold forged parts essentially have a good surface finish and dimensional accuracy to offer (Byrer 1985). In contrast, the operation of hot forging requires lower forces, but the dimensional accuracy and surface finish of the parts are often impaired (Byrer 1985; Dieter et al. 2003). Often, a forging must be subjected to additional finishing operations such as heat treatment to modify the properties and even machining for purpose of enabling accuracy in final dimension while concurrently ensuring a good surface finish. The above-mentioned finishing operations can be minimized by the precision forging technique, which is classified as a net-shape or near-net-shape forming process (Altan et al. 2005; Byrer 1985; Dieter et al. 2003).
Endogenous doesn’t always mean innocuous: a scoping review of iron toxicity by inhalation
Published in Journal of Toxicology and Environmental Health, Part B, 2020
Jody Morgan, Robin Bell, Alison L. Jones
Significant elevations were found for increased rates of lung cancer within the mining industry in Sweden. This was further analyzed as priori industry groups: metal mines; iron/steel mills; iron foundries; and blacksmith/welding (Jung et al. 2018). Despite an overall decrease in lung cancer rates among all miners in a Western Australian cohort, there was a significant rise for ever underground vs never underground for lung cancer with average annual radon exposure for Australian miners lower than the permissible limit (Sodhi-Berry et al. 2017). There was no marked change for iron ore only mining vs multiple ore mining exposure for lung cancer; however, these results were not compared to the general population as confounders such as employment-related variables and smoking were not accounted for (Sodhi-Berry et al. 2017). These results are in not agreement with an earlier study which found an elevated lung cancer risk at two hematite mines in China for underground workers Chen et al. 1990). Data were re-analyzed for those exposed pre and post-ventilation improvement in the mines with a marked reduced risk with the improvement in ventilation (pre-ventilation and post-ventilation); however, there was no adjusting for smoking or radon confounders in this study (Chen et al. 1990). There were significant increases over control for taconite miners exposed to low-grade iron ore, with co-exposure to silica and others: mesothelioma, lung cancer, laryngeal cancer; and stomach cancer (Allen et al. 2015). In contrast, other studies demonstrated no significant alteration in rates of lung cancer among hematite miners (Lawler et al. 1985).