There are two main types of low temperature pipe materials, austenite type and ferrite type. The difference in crystal structure determines that austenite type low temperature pipe has no brittle transition temperature in the low temperature range. Generally, it can be used without verifying its low temperature impact toughness. However, GB150-2011 stipulates that when the operating temperature is not lower than -196℃ (low temperature range), the impact test can be exempted. When the operating temperature is between -196～-253℃ (ultra-low temperature range), it needs to be implemented in accordance with the design documents. The ferrite-type cryogenic tube has an obvious low-temperature brittleness transition temperature, and has its applicable low-temperature range. Although various countries in the world have slightly different temperature limits for low-temperature steel, such as Britain, Germany/Japan, China, and the United States/Russia, the temperature limits defined by the United Kingdom, Germany/Japan, China, and the United States/Russia are respectively 0, -10, -20, -30℃, but the actual industrial environment can be lower. To -253 ℃ (liquid hydrogen) more than.
American standard seamless steel pipe
So far, only ASTMA333Gr.8 and Gr.11 steel pipes represented by ferrite-type low-temperature seamless pipes with service temperatures as low as -196℃ have been successfully commercialized. The production and use of tubes have developed special standards, such as EN10216-4 and GB/T18984. From the point of view of use, cryogenic pipes mainly include cryogenic pipes and cryogenic heat exchanger tubes. Compared with the national standard and the European standard that only make a single standard, Japan and the United States have formulated different standards for their purposes, such as JISG3460 for cryogenic pipes. And ASTMA333, and JISG3464 and ASTMA334 for low temperature heat exchanger tubes.