A kind of super high strength and high toughness maraging steel and its preparation method and application

Abstract

The invention provides a maraging steel with ultrahigh strength and high toughness. The maraging steel is prepared from the following chemical components by weight percentage: 18.0-20.0% of Ni, 15.0-18.0% of Co, 7.0-8.0% of Mo, 1.5-2.5% of Ti, 4.0-6.0% of Cu, less than 0.005% of C, less than 0.001% of O, less than 0.002% of N, less than 0.001% of P, less than 0.001% of S and the balance of Fe, wherein the total content of C, O, N, P and S is less than 0.01%. A copper-rich phase and Ni3Ti core-shell structure is formed in the maraging steel with ultrahigh strength and high toughness provided bythe invention; the compound reinforcement of soft and hard nano-particles is realized; no toughness is lost; the tensile strength is above 3000Mpa, the yield strength is above 2700Mpa and the ductility is above 10%; the maraging steel meets the requirements of cost reducing and benefit increasing of consumable materials, such as spinning crochet hooks, nail gun firing pins, and the like.

Description

technical field [0001] The invention relates to the technical field of maraging steel, in particular to an ultra-high-strength and high-toughness maraging steel and a preparation method and application thereof. Background technique [0002] Due to the advantage of material cost, high-strength low-alloy steel has always been the material of choice for enterprises specializing in the preparation of high-strength structural parts such as textile crochet needles and firing pins. Maraging steel is an ultra-high-strength steel based on carbon-free (or micro-carbon) martensite, which can produce intermetallic compound precipitation hardening during aging. Unlike traditional high-strength low-alloy steel, it does not use carbon but relies on metal The dispersion and precipitation of inter-compounds strengthens, which makes it have some unique properties: high strength and toughness, low hardening index, good formability, simple heat treatment process, maraging steel hardly deforms d...

AI Technical Summary

Problems solved by technology

Compared with high-strength low-alloy steel, although maraging steel has obvious advantages such as strength and toughness, it has not been recognized by relevant enterprises to realize industrial application

[0003] In the development process of maraging steel, strength-toughness matching and use cost are two core issues that affect the application prospect of maraging steel. On the one hand, the strength of maraging steel can be improved under the premise of ensuring toughness. , catering to the design purposes of product lightweight, energy saving and emission reduction, safety and environmental protection, etc., is a key factor in determining the application prospects of maraging steel; on the other hand, compared with ordinary high-strength low-alloy steel, maraging steel Although the advantages of strength and toughness are obvious, due to the high content of nickel, cobalt, molybdenum, titanium and other alloying elements, the material cost of maraging steel is relatively high, and it is difficult to popularize in practical applications.