Metal Component Nitriding with Intermittent Solvent Activation
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Solution Overview
Problem
Existing methods for activating the surface of metal components before gas nitriding or gas nitrocarburizing treatments, such as using chloride, fluorine, or carbon compounds, face challenges in automation, control of gas amounts, space requirements, gas leakage risks, and incompatibilities with mass flow controllers, making them inefficient and costly.
Innovation Solution
A processing method and apparatus that introduces a liquid organic solvent intermittently into a processing furnace through a pipe, allowing controlled introduction of activation gases, inhibiting vaporization and backflow, and enabling precise activation of the metal component surface by producing HCN or HCl through thermal decomposition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a chloride compound is used for surface activation, then the passivation film is destroyed and surface activation is achieved, but manual operation is required and the amount of produced HCl is difficult to control
Solution Approach 1:
The patent replaces manual mechanical operations with an automated liquid injection system. A liquid chloride compound (methylene chloride) is introduced through an injection needle into the processing furnace, where it vaporizes and decomposes to produce HCl. This substitution of manual solid compound handling with automated liquid injection achieves both reliable surface activation and operational automation.
2Reliability
If a chloride compound is used for surface activation, then the passivation film is destroyed, but the produced HCl reacts with ammonium to form ammonium chloride that accumulates and reduces corrosion resistance
Solution Approach 1:
The patent uses a liquid chloride compound that vaporizes and decomposes to produce HCl in controlled amounts. By using liquid methylene chloride instead of solid chloride compounds, the system achieves sufficient HCl production for passivation film destruction while maintaining better control over the reaction process, thereby reducing excessive HCl formation and subsequent ammonium chloride accumulation.
3Reliability
If a fluorine compound is used for surface activation, then the passivation film is changed to fluoride film and surface is activated, but highly-advanced detoxification treatment is required
Solution Approach 1:
The patent replaces expensive and complex fluorine compound systems with a simpler, more economical liquid chloride compound system. By using liquid methylene chloride that can be easily injected and vaporized, the invention achieves effective surface activation without requiring complex detoxification equipment, thereby simplifying the overall processing system while maintaining activation effectiveness.
4Reliability
If solid or liquid carbon compound is used for surface activation, then HCN is produced to reduce passivation film, but gas cylinder handling and leakage issues occur
Solution Approach 1:
The patent transitions from gas-phase carbon compound handling to liquid-phase injection followed by vaporization. Liquid methylene chloride is injected through a needle and vaporizes inside the processing furnace, eliminating the need for gas cylinders and associated leakage risks. This liquid-to-vapor approach maintains effective HCl production for surface activation while significantly improving operational safety and ease of use.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The method achieves effective surface activation with precise control of solvent introduction, reducing manual operations, minimizing solvent loss, and enhancing treatment reliability and productivity while avoiding corrosion and fatigue issues.
Implementation Method 1
When heated, the chloride compound is decomposed to produce HCl. The produced HCl destroys (denatures) the passivation film on the surface of the metal component
Implementation Method 2
the produced HCN reduces the passivation film on the surface of the metal component and activates the surface
Data Source
AI summary
The present invention is a processing method for a metal component by using a processing furnace. The method includes the steps of: introducing an activation atmospheric gas into the processing furnace; heating the activation atmospheric gas in the processing furnace to a first temperature; introducing a nitriding atmospheric gas or a nitrocarburizing atmospheric gas into the processing furnace; and heating the nitriding atmospheric gas or the nitrocarburizing atmospheric gas in the processing furnace to a second temperature. The activation atmospheric gas is introduced into the processing furnace through a pipe for introducing the activation atmospheric gas. A liquid organic solvent is introduced intermittently a plurality of times into the pipe for introducing the activation atmospheric gas which is under a state wherein the activation atmosphere gas continues to be introduced.