Cold working refers to the process of strengthening a metal by plastic deformation. Also referred to as work hardening, the metal working technique involves subjecting metal to mechanical stress so as to cause a permanent change to the metal’s crystalline structure.
The following properties are affected by cold work significantly:
- Tensile Strength
- Yield Strength
Advantages of cold work:
- Good dimensional control
- Good surface finish of the component.
- Strength and hardness of the metal are increased.
- An ideal method for increasing hardness of those metals which do not respond to the heat treatment.
Cold work refers to work with tools that may expose the user to hazardous situations such as:
- Working on electrical equipment within a hazardous environment. This should only be done when electrical power has been cut off and tagged;
- Opening up of pipelines and cargo equipment which may expose personnel to trapped toxic or flammable products; and
- Chipping and scaling of the ship’s structure which may cause contact sparking.
- Whenever cold work is planned within the cargo area or other hazardous areas, a permit to work should be issued for each intended task. The permit should specify the duration of validity, which should not exceed one working day.
The atmosphere within any enclosed space in which hot or cold work is to take place should be tested for hydrocarbons and a reading of less that 1 % LFL obtained on suitable monitoring equipment.