Understanding Mechanical Properties and Ferrous Materials

Posted on Jan 24, 2025 in Geology

Mechanical Properties

Elasticity: The capacity of a material to regain its original shape after being stretched.

Plasticity: The capacity of a material to retain its new shape after being deformed.

Ductility: The capacity of a material to be stretched into wires.

Malleability: The capacity of a material to be spread into sheets.

Hardness: The opposition a body offers to being scratched or penetrated by another.

Fragility: The opposite of tenacity. It is the tendency of a body to break under stress.

Resilience: The resistance a body offers to sudden shocks.

Tenacity: The resistance a body offers to breaking when subjected to stress-strain.

Fatigue: The deformation of a material over time.

Machinability: The ease with which a body can be machined by chip removal.

Acritude: The increase in hardness, brittleness, and resistance as a result of cold working.

Castability: The capacity of a melt to fill a mold.

Material Testing

Traction: Consists of slowly stretching a specimen of material until it breaks.

Fatigue: Consists of rapidly spinning a normalized cylinder of the material to be analyzed.

Hardness: Consists of applying a determined force with a diamond on the piece to be analyzed.

Resilience: Consists of determining the energy required to break a specimen of material by impact.

Oven

Parts

  1. Electric transformer
  2. Flexible cables
  3. Electrode arms
  4. Electrode supports
  5. Gantry with hydraulic swinging arms
  6. Refrigerated smoke outlet
  7. Structure

Operation

  1. The lid is removed, and flux is introduced.
  2. Scrap is added, the oven is closed, and the electrodes are brought close to the scrap to melt it.
  3. When the scrap is melted, oxygen is injected to remove impurities.
  4. The furnace is tilted, and the slag is extracted. Ferroalloys are added to the carbon.
  5. The oven is tilted, and the steel is poured into the ladle.

Classification of Ferrous Materials

  • Iron: Carbon content between 0.01% and 0.03%.
  • Steel: Iron-carbon alloys with carbon content between 0.03% and 1.76%.
  • Cast Iron: Carbon content between 1.76% and 6.67%.
  • Graphite: More than 6.67% carbon.

Commercial Presentations

  • Sheets: Rolled steel sheets that are between 1×2 and 3×3 meters.
  • Bars: Longer pieces. If the section is round and smaller than 5mm in diameter, it is called wire. If the thickness is very small and they are of great length, they are called strips.
  • Profiles: Hollow pieces of variable sections whose length ranges from 5×12 meters. They can be angular, IPN, T, tubular, square, and rectangular.

Foundries

Ordinary: Only has iron and carbon.

  1. White: Hard and brittle.
  2. Grey: Used in malleable foundries.
  3. Mottled: Intermediate properties between white and grey.

Alloyed: Contains other chemicals that enhance its properties.

Special: Uses premium ordinary materials.

  1. Malleable with a black heart: Uses white foundry. The piece is covered with sand and introduced into an oven at 900ºC for 6 days. It is then cooled for about 5 days.
  2. Malleable perlite: Introduced into an oven for 5 days and cooled for 2 days.
  3. Malleable spheroidal: Cerium and magnesium are added to the cast iron.
Environmental Impact of Ferrous Materials
  • Extraction: When obtaining raw materials, it causes noise impact, landscape alteration, and destruction of habitats. CO, CO2, tar, NH3, ash, and fumes are produced.
  • Processing: During the processing of ore into a commercial product, heavy metals, waste gas, dust, and noise are generated.
  • Disposal: It is important to dispose of or recycle used ferrous products properly.