Metallurgy - Nitriding, Alloying, Hardening

metallurgy

Table of Contents

Introduction
History of metallurgy
- Earliest development
  - Bronze
  - Iron
  - Brass
  - Precious metals
- From 500 bce to 1500 ce
- After 1500
  - Ferrous metals
  - Light metals
  - Welding
  - Metallography
Extractive metallurgy
- Pyrometallurgy
  - Roasting
    - Processes
    - Roasters
  - Smelting
    - Reduction smelting
    - Matte smelting
    - Electrolytic smelting
  - Refining
    - Fire refining
    - Electrolytic refining
    - Chemical refining
- Hydrometallurgy
  - Conversion
  - Leaching
  - Recovery
Physical metallurgy
- Structures and properties of metals
  - Metallic crystal structures
  - Mechanical properties
  - Electrical properties
  - Magnetic properties
  - Chemical properties
- Alloying
  - Processes
  - Metallurgy
    - Increasing strength
    - Increasing corrosion resistance
    - Reducing costs
    - Lowering melting points
- Casting
  - Processes
    - Sand-casting
    - Metal molds
    - Investment casting
    - Centrifugal casting
    - Continuous casting
  - Metallurgy
    - Grain size
    - Segregation
    - Porosity
- Metalworking
  - Processes
    - Rolling
    - Extrusion
    - Drawing
    - Sheet metal forming
    - Forging
  - Metallurgy
- Powder metallurgy
  - Applications
  - Processes
- Heat treating
  - Hardening treatments
  - Softening treatments
  - Processes
- Surface treating
  - Corrosion resistance
    - Barrier protection
    - Galvanic protection
    - Other coating techniques
  - Hardening
    - Carburizing
    - Nitriding
    - Other methods
- Metallography and metal testing
  - Metallography
    - Optical microscopy
    - Electron microscopy
  - Testing mechanical properties

References & Edit History Related Topics

Images & Videos

Catalan hearth or forge used for smelting iron ore until relatively recent times. The method of charging fuel and ore and the approximate position of the nozzle supplied with air by a bellows are shown.

Schematic diagram of a fluidized-bed roaster.

A side-blown copper-nickel matte converter.

Part of a modern potline based on the electrolytic Hall-Héroult smelting process.

Heap leaching of gold ore. Earth movers preparing the heap (background) and the drainage ditches for pregnant liquor (foreground).

The commonest metallic crystal structures.

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Nitriding provides an alternative means of hardening a steel surface. The surface layer is only one-tenth the depth of a carburized layer, but it is appreciably harder. The steel part is heated to a lower temperature, so that its crystal structure remains ferritic. Heating is conducted in an atmosphere of ammonia (NH₃) and hydrogen, and nitrogen from the ammonia diffuses into the steel. Hardening is accomplished in one of two ways. One way is solid-solution hardening, which occurs in all steels. The other way is precipitation hardening. For example, if a steel contains aluminum, the aluminum and nitrogen will combine ...(100 of 18633 words)

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