Metallurgical Vessel Lining Porous Structure Oxide Inclusion Control
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Solution Overview
Problem
Metal melts, particularly steel, are prone to oxide inclusions during continuous casting, leading to defects in the final product due to high reactivity with oxidative species, which existing methods fail to adequately prevent, resulting in significant production costs and scrap generation.
Innovation Solution
A lining for metallurgical vessels with a porous, non-oxidative material structure that creates an oxidation buffering layer at the interface between the metal melt and the vessel walls and floor, trapping metal melt and concentrating endogenous inclusions, thereby reducing their formation and diffusion into the bulk melt.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If aluminum is added to passivate iron against oxidation, then oxidation resistance is improved, but oxide inclusions still form in the melt
Solution Approach 1:
A porous intermediate layer is introduced between the refractory lining and the metal melt. This intermediate layer acts as a mediator that physically separates the metal melt from oxidative species in the refractory material, preventing oxidation reactions at the interface while allowing the melt to remain in contact with a protective barrier.
Solution Approach 2:
The intermediate layer is constructed with controlled porosity to allow selective interaction with the metal melt. The porous structure provides sufficient surface area for oxidation buffering while maintaining permeability characteristics that prevent inclusion formation, addressing both protection and purity requirements.
2Temperature
If refractory material lines the vessel walls and floor, then high temperature resistance is improved, but oxidative species are introduced to the melt
Solution Approach 1:
The porous intermediate layer serves as an intermediary barrier between the refractory lining and metal melt. It allows the refractory material to maintain its high-temperature structural function while preventing direct contact between the melt and oxidative species released by the refractory material.
Solution Approach 2:
The lining structure is modified by introducing a distinct intermediate layer with specific properties between the refractory material and metal melt. This creates local quality differentiation where the refractory layer provides thermal stability and the intermediate layer provides oxidation protection, with each layer optimized for its specific function.
3Productivity
If metal melt flows continuously through the vessel, then productivity is improved, but oxidation reactions increase due to extended reaction time
Solution Approach 1:
The porous intermediate layer provides continuous oxidation protection throughout the casting process. As metal melt flows continuously through the vessel, the intermediate layer consistently buffers oxidative species at the interface, allowing extended residence time without increased oxidation, thus maintaining productivity while reducing inclusions.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Substantially reduces the formation and spread of oxide inclusions by immobilizing metal atoms near the source of oxidative species, minimizing oxidation reactions and extending the oxidation reaction time beyond the casting operation, thus improving the quality and reducing production costs.
Implementation Method 1
a porous immobilizing layer lining said floor and at least some of the walls of the vessel, said immobilizing layer having an open porosity, with pores or perforations of diameter and surface energy such as to allow penetration therein by a metal melt
Implementation Method 2
The metal may remain in the molten form in the immobilizing layer, or may be partially or completely converted to the solid state in the immobilizing layer
Implementation Method 3
said refractory material being identified as a major source of reagents for the formation of endogenous inclusions, be it by diffusion of the ambient air or by reaction of some of the components thereof
Data Source
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AI summary
A lining for a metallurgical vessel is configured to have an engineered porosity. The lining contains a plurality of regions, each extending in a primary plane of the lining, each region having a differing value of total pore or perforation area as measured in a primary plane of the lining. The lining may be used to form part or all of the working surface of the floors or walls of the vessel. In casting use the lining produces an oxidation buffering layer at an interphase of metal melt extending from the interface between metal melt and the walls and floor of the metallurgical vessel, such that when in casting use, the metal flow rate in said oxidation buffering layer is substantially nil, and the concentration of endogenous inclusions, in particular oxides, in said oxidation buffering layer is substantially higher than in the bulk of the metal melt.