Surface plasma cladding method of metal turbine runner

Abstract

The invention relates to a surface plasma cladding method of a metal turbine runner. The problems of turbine runner blades such as surface hardness, wear resistance, corrosion resistance, shock resistance and prolonged service life can be effectively solved. The surface plasma cladding method comprises the following steps: a worktable of plasma cladding wear-resistant equipment is started to run so that a plasma torch moves to the position above cladding positions of the turbine runner blades; protective argon and a power supply for the plasma torch are started for arc striking to enter a plasma beam cladding process; under a direct current (DC) plasma beam at high temperature of 10,000-16,000 DEG C, iron-nickel alloy powder is synchronously transferred into the plasma beam of the plasma torch, and then the powder is rapidly heated into a molten or semi-molten state so as to perform mixed diffusion reaction with metal in a molten pool; as the plasma beam moves, the alloy molten pool is rapidly frozen into hard alloy coatings with thickness of 1-10mm; and after completion of cladding operation, grinding or polishing the hard alloy coatings on the surfaces of the blades. The surface plasma cladding method is simple; and by utilizing the method, the blades have the advantages of high hardness, high compactness, wear resistance and long service life.

Description

technical field [0001] The invention relates to a mechanical treatment method, in particular to a plasma cladding method on the surface of a metal water turbine runner. That is, the plasma cladding method is used to form a high-strength wear-resistant coating on the surface of the metal water turbine runner. This method can be widely used in the metal water turbine runner in the water conservancy industry. Background technique [0002] my country is a country rich in hydropower resources in the world. Hydropower has become one of the renewable energy sources that my country focuses on. The hydropower can develop a power capacity of 380 million kw and an annual power generation of 1.9 trillion kw.h, which is equivalent to 1.1 billion tons of raw coal. of power generation. But at the same time, my country's rivers have a large sediment content. The Yangtze River and its tributaries are characterized by high sand hardness, while the Yellow River is characterized by high sand co...

AI Technical Summary

Problems solved by technology

The laser surface quenching and hardening layer is thin, the equipment investment is large, and the maintenance cost is high; the cost of surface surfacing wear-resistant materials is high, and there is also the problem of surface processing difficulties; surface thermal spraying pre-treatment generally uses sandblasting, which has environmental pollution and coating processing Difficult, the combination between the coating and the substrate is a mechanical combination, and the coating is prone to fatigue and peeling off; due to the thin coating, the general thickness is tens of microns, and the working efficiency is very slow, it is used for medium and large hydraulic turbine runners reinforcement is not suitable

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