Cryogenic treatment process advantages

2012-05-16 15:47:00

With the continuous development of the machinery industry, the requirements for metal materials are becoming higher and higher. How to maximize the mechanical properties and service life of metal workpieces under the premise of materials and heat treatment processes has become the thinking and exploration of many frontiers in the heat treatment industry. The problem.

Advantages of cryogenic treatment process:

      After unremitting research by many researchers of metal materials at home and abroad, cryogenic and ultra-cryogenic treatment processes are considered to be the best method to solve the above problems, and their advantages are as follows:

      1. It transforms the retained austenite with lower hardness into harder, more stable martensite with higher wear resistance and heat resistance.

      2. Martensite grain boundaries, grain boundary edges, and grain boundary interiors are decomposed and refined, and a large amount of ultra-fine carbides are precipitated. During the cryogenic process of supersaturated martensite, the supersaturation is reduced, and the Fine carbides maintain a coherent relationship with the matrix, which can deform and reduce the martensitic lattice and reduce microscopic stresses, while finely dispersed carbides can hinder dislocation movement during the plastic deformation of the material, thereby strengthening the matrix structure; Due to the precipitation of ultra-fine carbides, which are uniformly distributed on the martensite matrix, the grain boundary catalysis is weakened, while the refinement of the matrix structure not only weakens the degree of segregation of impurity elements at the grain boundaries, but also plays a role in strengthening the grain boundaries. . As a result, the comprehensive mechanical properties of the material are improved in three aspects: improved toughness of the material, high impact toughness, improved tempering stability and fatigue resistance of the matrix; improved wear resistance; and improved dimensional stability. Thus, the purpose of strengthening the matrix, improving the quality of heat treatment, reducing the number of tempering, and extending the life of the mold is achieved.

      3. The internal thermal stress and mechanical stress of the material are greatly reduced after cryogenic treatment, and due to plastic rheology of micropores or stress concentration parts during the cooling process, compressive stress will be generated on the surface of such vacancies during the heating process. Such compressive stress can greatly reduce the damage of the workpiece to the local performance of the workpiece, thereby effectively reducing the possibility of deformation and cracking of the metal workpiece.