This article concerns distortion of a workpiece after induction-hardening under various conditions. It focuses particularly on the effects of quenching water temperature, PAG polymer concentration and the rotation speed of the workpiece during induction hardening. Electrical as well as non-electrical quantities which affect the process were monitored. They included the current passing through the inductor, the power frequency, quenching water temperature, the flow rate of the quenchant through the spray-quench device, the speed of rotation of the workpiece and some others. The workpiece was a cylinder 70 mm in length which contained a drilled off-axis through hole. Prior to hardening, dimensions of the workpiece and the hole were measured on three planes set in different distances from the bottom face. The measurement was repeated after induction hardening and the findings are reported in this article. Post-process hardness was measured on the cylindrical surface of the workpiece. Hardening depths obtained with different quenchants were measured.

No abstract

No abstract

No abstract

This paper aims to explain the mechanism of heat transfer between melt and cold crucible (CC) in processes referred to as induction skull melting (ISM). Several experiments were performed for this purpose. In these experiments, all relevant electrical and mechanical quantities that affect the heat transfer between the melt and the cold crucible were monitored. Firstly, this article deals with the description of the equipment used in the experiments. Aluminum oxide was considered as experimental material (EM). Therefore, the article also deals with the design of a suitable cold crucible for its melting. Subsequently, the article deals with the implementation of the experiment itself and its phases. Finally, based on the data obtained during melting processes, this paper deals with the calculation of the real heat transfer from the melt to the cold crucible. The main contribution of this article is a comprehensive view of the values of mechanical and electrical quantities that accompany the melting of the considered experimental material (EM) in the designed cold crucible. In conclusion, the values of thermal quantities obtained in the performed experiments are compared with numerical simulation.