Non-magnetic ventilation box iron material for nuclear power/hydropower station and preparing method of non-magnetic ventilation box iron material

Abstract

The invention belongs to the field of stainless steel material molding, in particular to a non-magnetic ventilation box iron material for a nuclear power / hydropower station and a preparing method of the non-magnetic ventilation box iron material. Ventilation box iron 0Cr18Ni9 comprises chemical components including 18%-19% of Cr, not larger than 4.0% of Mn, 8%-9% of Ni, not larger than 0.04% of C,not larger than 1.0% of Si, not larger than 0.035% of P, not larger than 0.020% of S, 2%-3% of Cu, 0.18%-0.22% of N and the balance Fe and inevitable impurities. The ventilation box iron 0Cr18Ni9 isobtained through technologies of burdening, electric-arc furnace smelting, AOD furnace refining, electroslag remelting, continuous mill operation, solution treatment, wire winding, acid pickling, drying, drawing, solution treatment, roll forming, cutting, checking, packaging, storage and the like in sequence. The preparation technology is simple, and oxidation machining is not needed. The stainless steel material prepared through the method has the beneficial effect that the austenite structure is stable, the magnetic conductivity is reduced while the strength is guaranteed, the condition thatthe magnetic conductivity mu is smaller than or equal to 1.1(H=15924 A / m), the beneficial effects of high ductility, good resistance to oxidation, good diamagnetism, resistance to intergranular corrosion and the like are achieved, and traditional 0Cr18Ni9 austenitic stainless steel can be replaced.

Description

technical field [0001] The invention belongs to the field of forming stainless steel materials, and in particular relates to a non-magnetic ventilation channel steel material for nuclear power / hydropower stations and a preparation method thereof. Background technique [0002] Ventilation channel steel material is used in the stator core of large and medium-capacity nuclear power / hydropower generators in the radial ventilation system, and is one of the essential components for the ventilation and heat dissipation of the stator core. The traditional 0Cr18Ni9 stainless steel material is due to the addition of high chromium and nickel (containing about 20% chromium and more than 8% Ni) in the steel, the internal structure of the steel presents an austenitic structure state, due to composition segregation or improper heat treatment during smelting , a small amount of martensite or ferrite structure will appear, and the stainless steel material will produce weak magnetism. Theref...

AI Technical Summary

Problems solved by technology

Therefore, although the traditional 0Cr18Ni9 stainless steel material has better corrosion resistance than Q235 structural steel, it has a high magnetic permeability {μ≥1.5 (H=15924A / m)} while ensuring strength

The level of magnetic permeability has a great influence on the super strong magnetic field generated by the rotor in the generator when it rotates at high speed. When the magnetic permeability μ≥1.10, it will interfere with each other and disturb the uniformity and stability of the original magnetic field. , resulting in a significant reduction in the power generation efficiency of the motor

And if you want the surface magnetic permeability of stainless steel to meet μ≤1.10, you need to carry out solid solution treatment, then the hardness and strength of the material itself will be reduced