Electrospark hardening method of surface of metal roll

Abstract

The invention discloses an electrospark hardening method of the surface of a metal roll and relates to a material surface hardening technology. The invention takes a cast steel roll as a deposition object, selects a ceramic hard alloy WC-Co electrode and carries out deposition processing under the atmosphere of argon protection. The technical parameters are as follows: the output power is 500 to 4000W, the output voltage is 60 to 180V, the discharge frequency is 1000 to 2000HZ, the deposition rate is 1 to 5min / cm and the flow rate of argon as protective gas is set to be 5 to 15L / min. Compared with the techniques of hot spraying, plasma cladding, vacuum sintering and the like, the electrospark hardening method has simple equipment needed and easy operation, does not need to carry out preheating to the work before deposition, does not need annealing treatment after deposition, does not generate hot damage to the surface of the metal roll and can carry out deposition repeatedly. The electrospark deposition layer after being treated forms a nano-micron fine crystalline structure, and the fine particles are distributed in a depositing layer in a disperse mode; the microhardness, wear resistance and high-temperature oxidizability of the depositing layer are greatly improved, thus prolonging the service life of the roll.

Description

technical field [0001] The invention belongs to material surface strengthening technology, and particularly provides an electric spark deposition method for forming a wear-resistant and high-temperature oxidation-resistant coating on the surface of a metal roll. A wear-resistant coating with a nano-micron structure is formed on the surface of a cast steel roll by an electric spark deposition method, and this technology can be widely used in the iron and steel metallurgy industry. Background technique [0002] In the metallurgical steel industry, as my country has become the largest manufacturing country in the world, and steel rolling is an important field in steel production, rolls are an important tool for steel plants to roll steel plates (steel strips) or steel bars, and are also One of the main consumable spare parts in production. The working conditions of the roll are generally very harsh. It has to bear very complex alternating loads and impacts, as well as the worki...

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Problems solved by technology

The laser surface quenching hardening layer has large equipment investment and high maintenance costs; surface intermediate frequency quenching, resistance furnace overall heating quenching, and differential temperature quenching methods are suitable for carbon structural steel and alloy structural steel, but the quenching hardening layer has poor heat resistance and cannot be used Hot rolling; the cost of surface surfacing wear-resistant materials is high, and there is also the problem of difficult surface processing; surface thermal spraying pretreatment generally uses sandblasting, which has environmental pollution, difficult coating processing, poor bonding between coating and substrate, and easy coating Fatigue spalling; the large-scale lasers required for laser cladding alloy layers are expensive, and there are many defects in the lap joints of laser cladding beams, and the post-processing of cladding layers is also difficult; the plasma cladding process is not easy to control, and the production cost is high. From a practical point of view, further in-depth research is needed

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