Maraging stainless steel and preparation method thereof

Abstract

The invention discloses maraging stainless steel and a preparation method thereof. The maraging stainless steel comprises 9.0-13.0 wt% of Cr, 11.0-15.0 wt% of Ni, 1.5-4.0 wt% of Mo, no more than 2.5 wt% of Cu, 1.2-1.9 wt% of Ti, no more than 2.0 wt% of Mn, no more than 2.0 wt% of Al, no more than 1.0 wt% of Si, less than 0.03 wt% of C, and the balance Fe. When an alloy is subjected to complete austenitizing and rapidly cooled to the room temperature, the alloy is in a supercooled austenite state, the material is in stress-induced martensite phase transformation to be transformed into a martensite state during cold machining, and the Vickers hardness increment Hv can reach 250-300 after aging treatment is conducted. The stainless steel is especially suitable for manufacturing small-sectional-area products like fishing hooks and medical suture needles.

Description

technical field [0001] The invention relates to a maraging stainless steel product composed of Cr, Ni, Mo, Cu, Ti and the balance being Fe, which is mainly used for the production of products with small cross-sectional size (such as thin steel wire with a diameter of less than 2mm, a thickness of less than 1mm thin steel strip) for the production of corresponding products that require high hardness (such as fishing hooks, medical suture needles, blades, springs, etc.). Background technique [0002] Maraging stainless steel is a type of stainless steel that does not contain C and contains alloying elements such as Cr, Ni, Ti, Cu, Mo, and Al. This stainless steel is in a martensitic state after high-temperature austenitizing solution treatment + rapid cooling. Since the alloy does not contain carbon, the alloy in the martensitic state has low strength and good plasticity, and can be processed by various machines. The processed parts are finally subjected to age hardening hea...

AI Technical Summary

Problems solved by technology

[0006] The above-mentioned existing maraging stainless steels have two common features: (1) the martensitic phase transition temperature is relatively high, and after high-temperature solid solution treatment, they are basically transformed into martensitic phase after being rapidly cooled to room temperature; (2) The hardness increment ΔHv obtained by aging is not high enough, generally ΔHv=150‐250

The main reason is that the contents of Mo and Ti were not increased at the same time.