Activation of self-passivating metals using reagent coatings for low temperature nitrocarburization in the presence of oxygen-containing gas
A method using pyrolysis products of nitrogen and carbon reagents in an oxygen-containing atmosphere activates and hardens self-passivating metals like stainless steel, addressing the Beilby layer issue and enabling effective case formation on complex shapes without pre-treatment, with enhanced properties and simplified industrial application.
Patent Information
- Application Number
- US19/317437
- Authority / Receiving Office
- US · United States
- Patent Type
- Applications(United States)
- Current Assignee / Owner
- Priority Date
- 2021-04-28
- Filing Date
- 2025-09-03
- Publication Date
- 2026-01-01
AI Technical Summary
Conventional low-temperature surface hardening methods for self-passivating metals like stainless steel, such as carburization, nitriding, and nitrocarburization, are ineffective on complex-shaped workpieces due to the presence of a Beilby layer, and require pre-treatment to remove this layer, while self-activating technologies fail to penetrate it effectively.
A method involving exposure to pyrolysis products of nonpolymeric reagents containing nitrogen and carbon in an oxygen-containing atmosphere at low temperatures, which activates and hardens the metal surface without the need for pre-treatment, allowing case formation even on complex shapes.
Enables effective case formation with enhanced properties like hardness, corrosion resistance, and abrasion resistance on self-passivating metals, including stainless steel, without the need for pre-treatment, and can be conducted in ambient air, reducing costs and simplifying industrial processes.
Smart Images
Figure US20260002244A1-D00000_ABST