金属材料深冷处理现状

Present development state of cryogenic treatment of metal

回顾了金属深冷处理的发展历史 ,简要介绍了工件经深冷处理后性能的变化 ,国内外对深冷处理提高工件性能及其机理的研究 .深冷处理的最新研究标定了弥散碳化物的晶体结构类型和大小并指出了其析出位置 ,提出金属韧性的提高主要是由于带状残余奥氏体分割马氏体从而保护了脆性相的论断 .通过特殊的装置观察到金属材料深冷过程中残余奥氏体→马氏体原位组织转变 ,并借助于正电子湮没实验发现有色金属和黑色金属在深冷过程中点缺陷的不同变化 ,为更好地解释深冷处理提高工件的性能提供了佐证 .

The development history of deep cryogenic treatment of meals is retrospected and the change in properties of the workpieces due to deep cryogenic treatment as well as the investigation of improvement of workpieces properties dice to deep cryogenic treatment and its mechanism at home and abroad are also introduced briefly. Recent investigation of deep cryogenic treatment has calibrated the types and dimensions of the crystalline structure of dispersed carbide and its release position is also pointed out. An inference is made that the improvement of the toughness of metals is basically caused by the dissection of martensite by the ribbon residual austenite, so that the brittle phase is protected. In situ structural transformation of residual austenite into martensite in the cryogenic process of metallic materials is observed with the help of a special facility and it is found by means of positron oblivion experiment that the variation of point defect in cryogenic process in different for the ferrous metals and nonferrous ones, providing a credible proof that deep cryogenic treatment is able to improve the properties of the workpieces. Finally, the development prospect of deep cryogenic treatment is given also in this paper.