What is the defined use of carbon steel in cryogenic applications?

In cryogenic applications, carbon steel is generally not suitable due to brittleness. At very low temperatures, carbon steel tends to lose its ductility and impact resistance, becoming more prone to cracking and failure. The physical properties of carbon steel can degrade significantly when exposed to extreme cold, which poses potential safety hazards in applications involving cryogenic fluids.

In contrast, materials such as stainless steel or specialized alloys are often preferred for cryogenic use because they maintain their structural integrity and toughness at low temperatures. Therefore, the inherent limitations of carbon steel in cryogenic environments underscore why it is not considered suitable for such applications.