The role of heat treatment process for large-diameter flanges

The heat treatment processes for large-diameter flanges mainly include quenching, tempering, normalizing, annealing, etc. Their functions mainly include the following aspects:

Enhance strength and hardness: Through heat treatment processes such as quenching, the microstructure of large-diameter flanges can be changed to form higher strength phases such as martensite, significantly improving the strength and hardness of the flanges, enabling them to withstand high pressure and tension, and meet the load-bearing requirements in engineering applications. For example, in some high-pressure pipeline systems, large-diameter flanges that have undergone quenching treatment can better withstand the pressure of the medium inside the pipeline.

The actual effect is mainly toughness and plasticity: Tempering process is usually used in conjunction with quenching, which can eliminate the internal stress generated during quenching, reduce the brittleness of the material, and improve high toughness and plasticity. This enables large-diameter flanges to have higher strength while also avoiding the risk of sudden fracture due to excessive brittleness, increasing the safety and durability of the flange during use.

Refining grain size: Normalization treatment can greatly refine the grain size of large-diameter flanges. The refined grain structure can improve the comprehensive mechanical properties of materials, including strength, toughness, fatigue performance, etc. At the same time, uniform and fine grains can effectively improve the machining performance of the main flange, making it easier to form during cutting, forging, and other machining processes, reducing machining defects.

Cancel residual stress: Large diameter flanges will generate residual stress during forging, welding, and other processing processes, which can affect the dimensional stability and mechanical properties of the flange, and may even lead to defects such as cracks during use. Annealing treatment is mainly used to eliminate residual stress, stabilize the structure and size of flanges, improve their accuracy retention, and prevent deformation during subsequent processing and use.