At Southwest Steel Casting Company castings can be heat-treated to bring about diffusion of carbon alloying elements, softening, hardenings, stress-relieving, toughening, improved machinability, increased wear resistance, and removal of hydrogen entrapped at the surface of the casting.

Steel's versatility is due to its response to thermal treatment. Heat treatment greatly increases the number of properties that can be obtained, because at certain 'critical temperatures' iron changes from one type of crystal structure to another. This structural change, known as allotropic transformation, is spontaneous and reversible and can be made to occur by simply changing the temperature of the metal.

Fundamentally, all steel heat treatments are intended to either harden or soften the metal. They involve one, or a series of operations, in which solid metal is heated and cooled under specific conditions to develop a required structure and properties. In general, the following major forms of heat treatment, for the standard steels, are used to modify properties to suit either fabrication or end use; Quenching, Tempering, Normalizing, Annealing and Stress Relieving.

To provide steel castings with the properties mention above, Southwest Steel Casting Company has installed a modern heat-treating facility which allows the following types of heat treatments to be performed:

      ► Water Quenching
      ► Tempering
      ► Normalizing
      ► Annealing
      ► Stress Relieving

In addition, the following services can be provided upon request:

      ► Oil Quenching
      ► Atmospheric Carburizing
      ► Flame Hardening

The heat-treating facilities at Southwest Steel consist of the following major components; three (3) 7' x 12' Car Bottom Furnaces equipped with automatic recording pyrometers, a high temperature gas fired Box Furnace (stainless), a 6,800 gallon capacity quench tank which includes a 2,200 gpm water circulation pump and 16,000 gallon capacity water reservoir and a dedicated Brinell testing line.