Effect of refractory and thermal insulation materials on heat-resistant steel alloy

Effect of refractory and thermal insulation materials on heat-resistant steel alloy
In industrial electric furnaces, in order to install heat-resistant steel components and prevent their deformation at high temperatures, supporting and supporting components made of refractory materials are required. There are also electric heating elements of some household appliances that are directly physical and powdery oxides. At this time, the surface of the electric heating alloy will directly contact with the refractory, and physical and chemical reactions will occur at high temperatures, thus eroding the electric heating element.
There are mainly corrosion and wear effects between the heat-resistant steel electric heating element and the refractory and thermal insulation materials in contact with it at high temperatures. Melting corrosion includes chemical corrosion and chemical corrosion and electric corrosion.

1. The role of chemical dissolution
A small amount of impurities in refractories and thermal insulation materials, such as FeO, P2O3, B2O3, etc., react with Al2O3 and Cr2O3 in the oxide film on the surface of heat-resistant steel elements at temperature, producing low melting point compounds, damaging the protective effect of the oxide film, and eroding the electric heating elements. It can be seen from the low melting point compounds mainly formed by a small amount of impurities and Al2O3 and Cr2O3 that V2O5, P2O5 and B2O3 are the impurity oxides that do great harm to electric heating elements. These impurity oxides corrode the electric heating element at low temperatures. Therefore, the content of refractory materials should be strictly controlled to avoid corrosion.
2. Abrasion action
When there is relative movement between the surface of the heat-resistant steel element and the supporting refractory, the protective oxide film on the surface of the element will be worn. The reason for relative movement is that the electric heating alloy expands when heated and shrinks when cooled. Although the relationship between this phenomenon and refractory materials is not very great, if the design is reasonable and the fixing is appropriate, this effect will be reduced.