Aluminum-strengthened maraging steel and preparing method thereof

Abstract

The invention discloses aluminum-strengthened maraging steel and a preparing method of the aluminum-strengthened maraging steel. The aluminum-strengthened maraging steel comprises, by weight percent, 0.01% to 0.2% of C, 6% to 24% of Ni, not larger than 6% of Mo, 0% to 4% of Mn, 0.5% to 6% of Al, 0% to 12% of Cr, 0% to 1.5% of Nb, 0% to 4% of Cu, 0% to 3% of W, 0.0005% to 0.05% of B and the balance Fe and inevitable impurities. Smelting is carried out according to ingredient compositions, and through forging, solid solution treatment and cold rolling heat treatment processes, the maraging steel is prepared, wherein the structure of the maraging steel is uniform, a high-density B2-NiAl intermetallic compound is a main strengthening phase of the maraging steel, and micro carbide and nanoclusters conduct joint strengthening on the maraging steel; and the maraging steel shows the excellent mechanical property, the tensile strength can reach 2.2 GPa. In addition, the main strengthening phase NiAl and a base body are in a coherent relationship, and the elasticity modulus and the base body are basically consistent.

Description

technical field [0001] The invention belongs to the field of ultra-high-strength maraging steel, and specifically relates to a new type of aluminum-reinforced martensitic steel containing no Co and mainly reinforced by NiAl. The steel has high elastic limit and good fatigue performance. Background technique [0002] Ultra-high-strength steel is a type of structural steel developed to meet the high specific strength materials used in the structure of aircraft, rockets and other spacecraft, and then used in conventional weapons, high-pressure vessels, etc. The tensile strength of traditional ultra-high-strength steel is 1400-2000MPa, but it is still insufficient in application. For example, low-alloy ultra-high-strength steel mainly strengthened by carbides will inevitably have a tendency to become brittle as the strength increases. At the same time, its high carbon content will inevitably lead to high heat treatment process requirements and complicated welding processes. Al...

AI Technical Summary

Problems solved by technology

Although this type of steel has excellent strength and toughness combination, its strengthening system itself and the matching relationship with the matrix make this type of steel insufficient in rigidity and have mediocre fatigue performance

In addition, it contains a large amount of alloying elements, especially the cost problems caused by expensive elements such as Co, which restricts the large-scale application of maraging steel

Afterwards, Co-free maraging steel was developed, such as US Patent 4443254 and British Patent 1355475, etc. These patents all adopt the method of increasing the content of Ti element and still using Ni 3 Ti is the main strengthening phase to achieve the strengthening effect, but the overall performance is significantly lower than that of Co-containing steel

As the main strengthening element, Ti has higher requirements on the carbon content in the steel, and the precise control of the content of alloying elements will also increase the cost.

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