一、前言随着国防工业和科学技术的迅速发展,以及新型钢种的出现,迫切地需要了解金属材料的低温机械性能,为了满足金属材料在低温下机械性能的试验,就要求材机行业提供一个工艺性好、热损失少的足以保证实现低温工作环境的试验装置,所以,在设计一 I. Introduction With the rapid development of national defense industry and science and technology and the advent of new types of steel, there is an urgent need to understand the low-temperature mechanical properties of metal materials. In order to meet the test of mechanical properties of metal materials at low temperatures, A good technological, heat loss enough to ensure that low-temperature working environment of the test device, so in the design of a