Cryogenics is an exciting, important and inexpensive technique that already has led to main discoveries and holds much future assurance. Cryogenic processing is the treatment of the materials at very low temperature around 77 K. This technique has been proven to be efficient in improving the physical and mechanical properties of the materials such as metals, alloys, plastics and composites. It improves the wear, abrasion, erosion and corrosion resistivity, durability and stabilizes the strength characteristics of various materials. Cryogenic refines and stabilizes the crystal lattice structure and distribute carbon particles throughout the material resulting a stronger and hence more durable material. In present paper, we have reviewed the effect of cryogenic treatment on some metals, alloys, plastics and composites.

Cryogenic Processing: A Study of Materials at Low Temperatures

Effect of welding structure on high-cycle and low-cycle fatigue properties for MIG welded A5083 aluminum alloys at cryogenic temperatures

Aluminum-magnesium alloys have an excellent combination of weldability, strength, and corrosion resistance, as well as exceptionally high toughness at room and low temperatures [1–11]. For these reasons, Al-Mg alloys are widely used for critical cryogenic applications, including the storage and ocean transportation of liquefied natural gas (LNG) [12–15].

Mechanical Properties of U. S./USSR Al-Mg Plate and Welds for LNG Applications

Aluminum and its alloys do not undergo abrupt transitions to a brittle state at low temperatures, and their ultimate strengths, yield strengths, and elongations at low temperatures are generally about as high or higher than those at room temperature. Aluminum alloys also possess good weldability and corrosion resistance. For these reasons, they are widely used as structural materials in the manufacturing of gas distribution equipment and tanks for storage and transportation of cryogenic liquids.

Fracture of Al-Mg6-Mn Plates and Welds at Cryogenic Temperatures

The application of liquefied gases in modern engineering requires materials suitable for service at temperatures approaching absolute zero. Aluminum and its alloys are not susceptible to sharp ductile-to-brittle transition at low temperatures and their ultimate tensile strength and yield strength are higher at low temperatures than at room temperature. Elongation of most aluminum alloys increases or remains constant with decreasing temperature. In addition, many aluminum alloys, including the Al-Mg alloys, possess good weldability. Therefore, aluminum alloys are widely used in vessels for storing and transporting LNG and other structures subject to extremely low temperatures. Selection of materials for use in LNG systems can be made by evaluating the properties of aluminum alloys and their welded joints over the low temperature range.

A. Ya. Ishchenko

Papers

Mechanical Properties of Soviet and American Al-Mg Alloy Plates and Welds for LNG Systems