The deformation of heat-resistant steel castings is a common casting defect. There are many reasons for the deformation of castings. The main reasons are summarized as follows:
1. The casting process of the casting is inappropriate
2. The structural design of the casting is unreasonable.
    Deformed heat-resistant steel castings change in size and shape. For the deformed heat-resistant steel castings, it can be corrected by mechanical or manual methods at room temperature or heating conditions.
Hot straightening is suitable for heat-resistant steel castings with poor plasticity, high strength, difficulty in cold straightening, or no large-scale straightening equipment for thick and large deformation castings.
    Thermal correction is divided into overall heating correction and local heating correction. Local heating correction is mainly suitable for large and medium-sized heat-resistant steel castings with a wall thickness of less than 60mm, as well as small and medium-sized heat-resistant steel castings with poor plasticity. Overall heating correction is mainly suitable for Large-scale heat-resistant steel castings with a wall thickness of more than 60mm.
    Cold rectification means rectification at room temperature, which is suitable for heat-resistant steel castings with simple shape, good plasticity and small wall thickness. Cold correction is generally carried out after heat treatment. For materials with poor plasticity, the correction range should not be too large. Cold correction should first correct the overall deformation, and then correct the local. The defects that are prone to occur during cold correction are mainly cracks and fractures. When the cold straightening process is inappropriate or there are defects inside the casting, cracks and fractures will occur after the straightening range exceeds the plastic value of the metal. After cold correction, important and complex castings should also be subjected to stress relief annealing to eliminate or reduce internal stress and ensure the mechanical properties of the castings.