Mechanical Properties and Industrial Treatments of Metals

Generic Properties of Metallic Materials

Metallic materials offer great value for volume resistance. They possess a significant capacity to withstand mechanical stress, although some properties are antagonistic. They exhibit good behavior toward external actions and possess the property of hardness. Deformability and elasticity are fundamental aspects of their nature.

Specific Properties and Characteristics

• Malleability: The ability to adapt plastic characteristics with a small thickness; its morphology favors linear forms.
• Ductility: A property of a body to lengthen; it can easily be drawn into wire.
• Tenacity: Tends to prevent internal strain and resist breaking.
• Ultimate Tensile Strength: Resistance increases sharply when the material is deformed.
• Brittleness: The tendency to break without significant deformation.
• Hardness and Resilience: Resistance to surface damage and the capacity to absorb energy.
• Solderability: The ease with which a metal can be welded.
• Oxidisability: The tendency to react with oxygen.
• Electrical and Thermal Conductivity: High capacity to conduct heat and electricity.
• Solid Structural Compactness: High capacity for plastic and elastic deformation, opacity, and gloss.

Metal Forming and Processing

Forge: Providing a material with a specific shape by hitting it (e.g., soft iron).

Lamination (Rolling): Most commonly using a pair of rollers to give a specific thickness.

Drawing: Stretching the metal to reduce its cross-section.

Molding: Melting and pouring the material into a bowl or mold of the desired shape and waiting for it to cool.

Steel Treatments and Manufacturing

Mechanical Treatments

These are tools used to give an adequate shape. They can be cold (temperature below crystallization) or hot (temperature above crystallization). Types of treatments include:

• Forge: Shaping through beatings.
• Rolling: The part passes between two rollers.
• Drawn: Hot or cold stretching of the metal to make thread or wire.
• Molding: Liquid material is placed in a mold to achieve a desired shape.

Heat Treatments

Heating or cooling the material under a known law to change its size, grain quality, and microstructures. Types include:

• Normalized: Heated to temperatures above the melting point and cooled outdoors to create a soft and ductile material.
• Quenching (Temple): Heated to a temperature above the standard and cooled quickly to make the material harder and more resistant to traction.
• Annealing: Heating the metal and cooling it slowly.
• Temper (Tempering): Performed after quenching; the cooling is slower than the quenching process.

Surface Treatments

The change will occur by heating combined with the application of more chemicals.

Corrosion and Oxidation

• Electrochemical Corrosion (Wet Corrosion): Occurs when metal is in contact with water, salt solutions, or acids.
• Dry Corrosion or Oxidation: A combination of metals with the surrounding environment; there is no intervention by water, but rather by oxygen from the atmosphere.

Methods of Protection

These methods include maximizing the properties of metals and isolating them from aggressive environments. This is achieved by correctly choosing and using metal alloys, corrosive-resistant materials, and seamless homogeneous materials.