Martensite ageing stainless steel with high strength and high toughness

Abstract

This invention relates to a high-strength and high-toughness maraging stainless steel, whose chemical composition is: C less than or equal to 0.02 wt.%, Si less than or equal to 0.1 wt.%, Mn less than or equal to 0.1 wt.%, S less than or equal to 0.01 wt.%, P less than or equal to 0.01 wt.%, Cr 10.0-11.5 wt.%, Ni 11.7-12.5 wt.%, Mo 0.5-2.0 wt.%, Ti 1.2-1.7 wt.%, Al 0.02-0.5 wt.%, and Fe as balance. The strength of the maraging stainless steel is 1700-1800 MPa. The maraging stainless steel has such advantages as low cost, high strength, high fracture toughness, and high corrosion resistance.

Description

technical field [0001] The invention belongs to the field of stainless steel, in particular to a high-strength and high-toughness maraging stainless steel, the strength of which reaches 1700-1800 MPa. Background technique [0002] In the existing technology, with the development of science and technology and the progress of human civilization, the development of metal materials with corrosion resistance has become an inevitable trend and a goal pursued by science and technology. Because corrosion not only loses material, damages component surfaces, and degrades material properties. According to a report in 2006, the direct loss caused by material corrosion in the United States is 279 billion US dollars per year, which is equivalent to 3.2% of the national GDP. If the cost of surface treatment such as cadmium plating and damage to the environment are considered, the loss caused by material corrosion is even more alarming. . [0003] As we all know, the steel with strength e...

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Problems solved by technology

However, it does not contain Cr elements, or the Cr content is very low, and the corrosion resistance is poor. In order to improve its corrosion resistance, surface protection measures such as cadmium plating must be used. However, due to the pressure of environmental improvement, the processing cost of the plating solution has been increasing. Therefore, it is not a long-term solution to improve the corrosion resistance of metal materials through surface treatment. Therefore, although steel types such as maraging steel have good strength and toughness, their use is still more and more limited.

Traditional precipitation-hardening stainless steels such as PH13-8Mo and 17-4PH have good corrosion resistance, but their strength is low and their toughness is insufficient, which seriously affects the safety and reliability of components. Under the condition of 1700MPa, the fracture toughness is 80MPa m 1 / 2 left and right, low toughness

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