Stress-relief annealing is a heat treatment that is used to reduce internal stresses in the structure of the material and thereby reducing the risk of dimensional changes during further manufacturing or final use of the product. It is not practically possible to manufacture a cast product without internal stresses owing to different rates of cooling within the product. The size and direction of these internal stresses are dependent on the geometry of the cast components, their design, and the processes conditions during casting. Stress relief annealing is done at temperature between 500-550°C, which are below the area of eutectoid transformation, so an unwanted change in structure and therefore a change in the mechanical properties during the annealing process is avoided.
Stress relieving can be carried out for GJS- and GJL-grades upon request.