Thermal bimetallic material taking electrical pure iron as middle layer and preparation method of thermal bimetallic material

Abstract

The invention discloses a thermal bimetallic material taking electrical pure iron as a middle layer and a preparation method of the thermal bimetallic material. The thermal bimetallic material is of a layered structure and comprises an active layer, a passive layer and the middle layer sandwiched between the active layer and the passive layer, wherein the active layer is made from iron-nickel-chromium FeNi22Cr3, the middle layer is made from the electrical pure iron, and the passive layer is made from ferronickel FeNi36. The thermal bimetallic material disclosed by the invention has good flexivity, resistivity, welding performance and corrosion resistance, and perfect balance between low cost and corrosion resistance is achieved; in addition, by the preparation method disclosed by the invention, the bonding strength among the layers of the prepared thermal bimetallic material can be relatively high, and bonded interfaces can be flat and straight and be free of cracking phenomena.

Description

technical field [0001] The invention relates to a thermal bimetal material and a preparation method thereof, in particular to a thermal bimetal material with electrical pure iron as an intermediate layer and a preparation method thereof, belonging to the technical field of metal materials. Background technique [0002] Thermal bimetallic material is a functional temperature-sensitive material, which is composed of two or more materials with different thermal expansion coefficients. Among them, the active layer is made of materials with larger thermal expansion coefficients, and the passive layer is made of materials with smaller thermal expansion coefficients. It can produce shape changes according to temperature changes. It is mainly used in the fields of thermostats, low-voltage electrical appliances and instruments, such as: used for overload protection of low-voltage circuit breakers. When the current is overloaded, the temperature of the material will rise and the bimeta...

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Problems solved by technology

At present, the annual demand for such thermal bimetal materials with pure nickel as the intermediate layer is about 2,000 tons. Because nickel is an expensive non-ferrous metal, the production cost is very high. In order to reduce the production cost of thermal bimetal, it is necessary to develop low Low-nickel or nickel-free interlayer thermal bimetallic materials

[0004] Chinese patent CN201410157022.9 discloses a layered thermal bimetallic material that can save nickel. The middle layer of the thermal bimetallic material does not use pure nickel, but a layered composite alloy of copper alloy layer and steel alloy layer. Combination layer, the number of layers of the alloy combination layer is 2-4 layers, the thickness of the alloy combination layer accounts for 5%-40% of the total thickness of the thermal bimetallic material, and the material of the copper alloy layer is any of C11000 or C10200 or C10700 The material of the steel alloy layer is either SUS430 or SUS304; although this patent saves the amount of nickel, the price of the copper alloy layer and steel alloy layer used in the middle layer is still relatively expensive, and the production cost is still high

In the above-mentioned patents, the alloy combination layer of electrical pure iron or copper alloy layer and steel alloy layer is used to replace the pure nickel intermediate layer used in bimetallic materials, which saves the amount of nickel, although the production cost is reduced to a certain extent. , but due to the absence of the pure nickel intermediate layer, its corrosion resistance is reduced, and the thermal bimetallic materials used in low-voltage electrical appliances have high requirements for corrosion resistance, which makes the above thermal bimetallic materials unable to meet the use requirements

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