Surface modified steel member with anti-corrosion properties and method for modifying surface of steel material
AssigneeChongqing Dayou Surface Technology Co., Ltd.
InventorYU-ZHONG REN
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Abstract
A steel member with surface modified during manufacture has good anti-corrosion properties. The steel member includes a steel substrate, a metallic diffusion layer formed on the steel substrate, and an alloy deposition layer formed on the metallic diffusion layer. The steel substrate is made of medium-carbon steel or medium-carbon alloy steel. After cleaning and heating processes are applied, the metallic diffusion layer includes pearlite and ferrite crystals and hardness of the surface is also enhanced. The alloy deposition layer includes zinc ferrum alloy. The metallic diffusion layer and the alloy deposition layer have a total Micro Vickers Hardness in a range from 240 to 500.
Claims15
A surface modified steel member with anti-corrosion properties, comprising:
- a steel substrate made of medium-carbon steel or medium-carbon alloy steel, the steel substrate comprising carbon element which has a content in a range from 0.3% to 0.65% in the steel substrate by weight;
- a metallic diffusion layer formed on the steel substrate, the metallic diffusion layer comprising pearlite crystals and ferrite crystals;
- and
- an alloy deposition layer formed on the metallic diffusion layer opposite to the steel substrate, the alloy deposition layer comprising zinc ferrum alloys;
- wherein the metallic diffusion layer and the alloy deposition layer have a total Micro Vickers Hardness in a range from 240 to 500.
A method for modifying surface of steel material, comprising:
- providing a steel substrate which is made of medium-carbon steel or medium-carbon alloy steel, the steel substrate comprising carbon element which has a content in a range from 0.3% to 0.65% in the steel substrate by weight;
- pretreating the steel substrate to clean surfaces of the steel substrate;
- providing a penetrating agent, the penetrating agent comprising Zn powder in a range from 25% to 30% by weight, Ni powder in a range from 2% to 2.5% by weight, Al powder in a range from 1% to 2.5% by weight, rare earth metallic powder in a range from 0.5% to 1.5% by weight, ammonia chloride in a range from 1% to 4% by weight, and Al2O3 powder in a remaining range by weight;
- loading the steel substrate after the pretreatment and the penetrating agent into an enclosed steel container, heating the steel container to a temperature in a range from 370 degrees Celsius to 430 degrees Celsius, and rotating the steel container at a speed in a range from 5 RPM to 10 RPM during the heating, thereby causing the penetrating agent to diffuse into the steel substrate to modify the surface of the steel substrate;
- washing the steel substrate after the surface modification, thereby obtaining the surface modified steel member.
Dependencies are inferred from the claim text.