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Multi-objective parametric optimization of wire electric discharge machining for Die Hard Steels using supervised machine learning techniques
Published in Rajeev Agrawal, J. Paulo Davim, Maria L. R. Varela, Monica Sharma, Industry 4.0 and Climate Change, 2023
Pratyush Bhatt, Pranav Taneja, Navriti Gupta
Hardened steel is produced by applying heat treatment, quenching and subsequent reheating processes on plain carbon steel. Hardened steel possesses resistance to wear, severe abrasion as well as impact and shock forces [1]. Corrosion-resistant coating (generally chromium coating) can be applied to die steels in order to further improve their resistive properties. Components made of hardened steel have a hard exterior casing [2,3]. Some of the components made from hardened steel are arbors, axles, driving pinions and camshafts. Components made from hardened steel find extensive application in fields such as power production, transportation and general manufacturing engineering [4]. These mechanical properties make hardened steel the most widely used material for dies and other cutting tools. But these properties are also responsible for making hardened steels difficult to machine using conventional machining techniques. The material remains brittle even after tempering and, thus, it sustains damage from sharp impacts. Thus, precision machining of the alloy becomes a great challenge.
Introduction to Friction Surfacing
Published in B. Ratna Sunil, Surface Engineering by Friction-Assisted Processes, 2019
Particularly for steels, several surfaces or case hardening methods were developed in which increasing the hardness and wear resistance by martensite transformation at the surface up to certain depth is the main objective. Martensite is a nonequilibrium phase resulted when diffusionless phase transformation is happened in steels during cooling. The heat treatment process which results matersite phase after cooling is called as hardening that involves heating the component to certain temperature (above the upper critical temperature in the iron-iron carbide phase diagram) and cooling to room temperature such a way the phase transformation from pearlite to ferrite + cementite is interrupted. The carbon usually must diffuse out during the phase transformation is entrapped in the lattice, and instead of body-centered cubic (bcc), body-centered tetragonal (bct) crystal structure is resulted which is known as martensite. The mechanical properties of hardened steel are superior in hardness and wear resistance compared with non-heat treated steels. Martensite transformation depends on the carbon content of the steel. Low carbon steels are difficult to get martensite transformation. High carbon steel can be easily undergone martensite transformation. However, follow up tempering process is also required to control the brittleness that is induced due to the hardening. By transforming the surface of a component to martensite up to a certain thickness, the corresponding hardness and wear resistance can be increased without affecting the core.
Milling Operations and Machines
Published in Zainul Huda, Machining Processes and Machines, 2020
There are two main forms of milling operation: (a) peripheral milling and (b) face milling. In peripheral milling, the cutter axis is oriented parallel to surface being machined, and the cutting edges are provided on outside periphery of the cutter (see Figure 7.1a). It has experimentally been shown that successful surface finishing of hardened steel can be achieved by peripheral milling (Hayasaka et al., 2017). In face milling, the cutter axis is normal to the surface being milled, and cutting edges are provided not only on the outside periphery of the cutter but also on its end (see Figure 7.1b).
Geometrical shape improvement of steel moulds by robot polishing process for polymer optic replication
Published in Production & Manufacturing Research, 2018
Rui Almeida, Rainer Börret, Mario Pohl, David K. Harrison, Anjali K. M. De Silva
From the previous works it is concluded that the same material removal’s depth is achieved and reproduced on plastic samples, soft steel and hardened steel (Almeida & et al., 2017a). To apply such a polishing correction technique, it is of great importance to always achieve the same material removal while using the same set of polishing parameters and experimental procedure. Hardened steel is used for the production of moulds, which are used for plastic injection moulding. For this reason, the polishing correction technique is applied on hardened steel with the goal to improve the flatness.