Diffusive Steel Scrap Melting in Carbon-Saturated Hot Metal—Phenomenological Investigation at the Solid–Liquid Interface

Materials

Johannes Schenk¹  FlorianMarkus Penz¹  Krzysztof Pastucha²  Michael Reischl³  Gerald Klösch⁴  Rainer Ammer⁵ 

[1] K1-MET GmbH, Stahlstraße 14, A-4020 Linz, Austria;Primetals Technologies Austria GmbH, Turmstraße 44, A-4020 Linz, Austria;voestalpine Forschungsservicegesellschaft Donawitz GmbH, Kerpelystraße 199, A-8700 Leoben, Austria;voestalpine Stahl Donawitz GmbH, Kerpelystraße 199, A-8700 Leoben, Austria;voestalpine Stahl GmbH, voestalpine Straße 3, A-4020 Linz, Austria;

关键词: steelmaking;    basic oxygen furnace;    scrap dissolution;    scrap melting;    thermodynamics;    kinetics;   

DOI  :  10.3390/ma12081358

来源: DOAJ

【 摘 要 】

The oxygen steelmaking process in a Linz-Donawitz (LD) converter is responsible for more than 70% of annual crude steel production. Optimization of the process control and numerical simulation of the LD converter are some of the current challenges in ferrous metallurgical research. Because of the process conditions and oxidation of impurities of the hot metal, a lot of chemical heat is generated. Therefore, steel scrap is charged as a coolant with the economical side aspect of its recycling. One of the more complex aspects is, among others, the dissolution and melting behaviour of the scrap in carbon-saturated hot metal. Heat and mass transfer act simultaneously, which has already been investigated by several researchers using different experimental approaches. The appearances at the interface between solid steel and liquid hot metal during diffusive scrap melting have been described theoretically but never investigated in detail. After an experimental investigation under natural and forced convective conditions, the samples were further investigated with optical microscopy and electron probe microanalysis (EPMA). A steep carbon concentration gradient in the liquid appeared, which started at an interface carbon concentration equal to the concentration on the solid side of the interface. Moreover, the boundary layer thickness moved towards zero, which symbolized that the boundary layer theory based on thermodynamic equilibrium was not valid. This fact was concluded through the prevailing dynamic conditions formed by natural and forced convection.

【 授权许可】

Unknown