Embrittlement metal

The low temperature which, if the materials come into contact with the body, can cause severe tissue burns. Flesh may stick fast to cold uninsulated pipes or vessels and tear on attempting to withdraw it. The low temperatures may also cause failure of service materials due to embrittlement metals can become sensitive to fracture by shock. 

Step 3. Methane gas evolves during decarburization corrosion and builds up pressure, causing hydrogen embrittlement metal fatigue and eventual tube ... 

Beachem CD. A new model for hydrogen-assisted cracking (hydrogen embrittlement). Metall. Trans. 1972 3 437 51. 

Hydrogen stress cracking of embrittled metal is caused by static external stresses, transformation stresses (for example, as a resnlt of welding), internal stresses, cold working, and hardening. As a rule, cracking does not occur in dnctile steels or in steels that have received a proper post-weld heat treatment. 

This choice and the resulting approximations are best illustrated by two examples. In the first, we consider hydrogen diffusion in metals. This diffusion substantially reduces a metal s ductility, so much so that parts made from the embrittled metal frequently fracture. To study this embrittlement, we might expose the metal to hydrogen under a variety of conditions and measure the degree of embrittlement versus these conditions. Such empiricism would be a reasonable first approximation, but it would quickly flood us with uncorrelated information that would be difficult to use effectively. 

Gibala R and Hehemann R F (eds) 1984 Hydrogen Embrittlement and Stress Corrosion Craoking (Metals Park, OH American Soceity of Metals)... 

Properties. Most of the alloys developed to date were intended for service as fuel cladding and other stmctural components in hquid-metal-cooled fast-breeder reactors. AHoy selection was based primarily on the following criteria corrosion resistance in Hquid metals, including lithium, sodium, and NaK, and a mixture of sodium and potassium strength ductihty, including fabricabihty and neutron considerations, including low absorption of fast neutrons as well as irradiation embrittlement and dimensional-variation effects. Alloys of greatest interest include V 80, Cr 15, Ti 5... 

S tandard Methods of Test for Hydrogen Embrittlement of Copper, ASTM B 577, American Society for Testing and Materials, Philadelphia, Pa., 1992. Welding Braying and Soldering Vol. 6, Metals Handbook, 9th ed., ASM International, Materials Park, Ohio, 1983. 

Analysis methods for hydrogen absorbed in the deposit have been described (65), and instmments are commercially available to detect hydrogen in metals. Several working tests have been devised that put plated specimens under strain and measure the time to failure. A method for cadmium-plated work has been described (66) as has a mechanical test method for evaluating treatments on AlSl 4340 Steel (67). Additional information on testing for hydrogen embrittlement is also available (68). 

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