Many industries require materials that are highly resistant and that do not lose their ductility in cold environments. For this reason, most of them choose to use stainless steel products.
Unlike metals such as iron, chromium or tungsten, some stainless steel alloys are well suited to such environments, where they will be exposed to temperatures below 0°.
The different characteristics of these materials will depend on various factors such as crystalline structure, grain size, tendency to absorb contaminants from the steel atmosphere, heat treatment, slag entrapment and processes such as melting, welding, chip removal and deformation.
To find out which grades of stainless steel are best suited to working at low temperatures, read on in the following Tisco Steel article.
Up to -45 °C
Types of stainless steel resistant to low temperatures 45
This first threshold is important because it is usually the lower limit of the temperature naturally reached on earth and the temperature at which some industrial operations and chemical processes take place.
Unfortunately, structural steels are not suitable for use at this level because of their intrinsic properties or because they are not normally tested for hardness and strength at low temperatures. However, some steel mills have special carbon steels for these applications. These are mainly low-alloy steels that have been hardened and tempered.
PH stainless steels, i.e. precipitation-hardened stainless steels, are not suitable for use at temperatures below -20°C because of the brittleness and cracks that can form on their surfaces.
At this temperature, all aluminium and titanium alloys can be used.
Up to -75 °C
Some steels can be used at these temperatures, such as low-alloyed steels, hardened and tempered steels or ferritic nickel steels. Most low carbon martensitic steels (0.20-0.35%) can be used with sufficient reliability.
Many of these alloys contain manganese, nickel, chromium, molybdenum and vanadium, as well as some zirconium and boron.
Up to -100 °C
Mild steel and 3.5% nickel steel are often used for liquid gas storage tanks at temperatures down to -100 °C. In addition, many aluminium alloys, nickel alloys and titanium alloys are also suitable for these temperatures.
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Up to -196°C
All austenitic stainless steels in the 300 series are suitable for operation in this temperature range, as are martensitic steels with a nickel content of between 20% and 25%, and steels with added cobalt, molybdenum, titanium, aluminium and niobium. The latter type has excellent ductility, toughness and hardness properties and must be hardened at temperatures of 400°C.
On the other hand, many aluminium alloys have excellent fracture toughness if exposed to temperatures of -196°C; this is not the case for welds. Other alloys that resist even lower temperatures are aluminium-magnesium alloys.
Nickel-based materials are almost always resistant to -196°C. Titanium alloys are also suitable, but must be kept free of impurities such as oxygen, nitrogen, carbon and iron, which can cause brittleness.
Below -196 °C
These low temperatures are of great interest to industry because they correspond to the temperatures at which helium (-270 °C) and hydrogen (-253 °C), a promising element for energy storage and nuclear fusion projects, liquefy at these temperatures.
Of these steel grades, only high-alloyed austenitic stainless steels are suitable for these temperatures, such as 304 and 310. If welding is required, the use of low-carbon variants is recommended. These typically contain between 18% and 21% chromium and 9% to 14% nickel.
As you can see, 300 series stainless steel offers an excellent combination of strength and weldability at low temperatures, so try to use it in similar environments.