Higher operating temperatures and classifications of electrothermal alloys

The highest ambient temperature that can be used for electric heating alloys refers to the highest working temperature that the surface of the electric heating element is allowed to reach in dry air. The heating system solution for the new energy vehicle battery heater to solve the low temperature environment charging of the power battery: the silicone heating system is a very thin pure resistive heating sheet, which is very soft and has a thickness of 1.5MM. The oil drum heating belt adopts the soft and bendable characteristics of the silicone heating plate. The metal buckles are riveted on the reserved holes on both sides of the heating plate, and the spring buckles are buckled on the barrel, pipe and tank. It is easy and quick to install. The silicone rubber heating plate can be made to be close to the heated part by the tension of the spring, which heats quickly and has high thermal efficiency. The silicone rubber heating belt is a particularly soft heating belt composed of nickel-chromium alloy wire and insulating material. It has a high design power density, fast heating, high thermal efficiency and long service life. In addition to being used for heating and heat preservation of general constant power belts, it can also be used in places where heating is required in some cases. When the electric heating element is heated in an open state, the different temperatures on the surface of the electric heating element material are about 50~100℃ higher than the furnace temperature. When heating begins in a closed state, the surface treatment temperature of the electric heating element is about 100~150℃ higher than the furnace temperature.

According to the highest ambient temperature of use, the electric heating alloy can be mainly divided into the following four different grades: ultra-high temperature electric heating alloy, high temperature electric heating alloy, medium temperature electric heating alloy, and low temperature electric heating alloy.

High temperature electric heating alloy

The temperature of ultra-high temperature electric heating alloy is 1400 degrees Celsius. It is used to manufacture electric heating elements in furnaces with an operating temperature of 1200 to 1300 degrees Celsius. The chemical composition of the alloy belongs to the iron-chromium-aluminum system. In order to ensure the performance of the alloy at high temperatures, this golden combination contains high chromium and aluminum. Among them, chromium is 22% to 28%, aluminum is 6% to 8%, and it also contains a small amount of cobalt, cadmium, titanium and trace amounts of uranium, uranium, and rhodium. This combination includes steel embryos made by powder metallurgy, and processed electric heating alloy wires and strips.

Ultra-high temperature electric heating alloys are mainly used in single crystal diffusion furnaces, powder metallurgy product sintering furnaces, ceramic calcining furnaces and high temperature heat treatment furnaces, with an operating temperature of 1200-1300°C.

Ultra-high temperature alloys are 0Cr26Al7.5; 0Cr27Al7Mo2, 0Cr24Al6R, 0Cr22Al6Core and 0Cr22Al5.8, 0Cr23Al6, all of which are produced by powder metallurgy.

2. High temperature electric heating alloys

The operating temperature of high temperature electric heating alloys is 1300°C, and they are mainly used for the manufacture of 1100-1200°C electric heating elements for heating furnaces. This group of electric heating alloys also belongs to the iron-chromium-aluminum series. The chromium and aluminum content in this group of alloys is slightly lower than that of ultra-high temperature alloys, containing 22%-25% chromium, 4%-6% aluminum, and also contains a small amount of molybdenum, niobium, cobalt, titanium and rare earth metal elements.

High temperature electric heating alloys are mainly used to manufacture electric heating elements for heat treatment furnaces such as quenching, normalizing, annealing, and solution treatment, as well as electric heating elements for copper, aluminum, and their alloy melting furnaces.

They belong to high temperature electric heating alloys 0Cr25Al5, 0Cr21Al6Nb, 0Cr23Al6, etc.

3. Medium temperature electric heating alloys

The working temperature of medium temperature electric heating alloys is 1100℃. It is mainly used to manufacture electric heating elements for heating furnaces with working temperatures of 850-950℃, such as high temperature tempering furnaces, aluminum melting furnaces, household appliances, etc. This type of electric heating alloy has good plasticity and can be processed into complex-shaped electric heating elements at room temperature. This type of electric heating alloy includes: nickel-chromium alloy cr30ni70, Cr20Ni80, Fe-Cr-al alloy 0cr23al5, 0cr20al3, 0cr19al5, 0cr21al6, etc.

4. Low temperature electric heating alloys

The use temperature of low temperature electric heating alloys is lower than 950 ° C. They are mainly used to manufacture heating furnace electric heating elements with working temperature lower than 800-750 ° C, such as low temperature tempering furnaces, drying furnaces and household appliances. This type of electric heating alloys includes cr15ni60, cr20ni35, cr20ni25 and 1cr13al4,0cr19al3.