Actually, cryogenic vessels do not really fail, in the sense I think you mean, over time—with the notable exception of liquid helium and liquid hydrogen storage vessels. Liquid helium has bizzare effects of metal (in addition to quantum tunneling) causing high strength steel to embrittle over time. It is thoought that this occurs due to the presence of helium in solid solution in the metal subjected to loading, and being present at a temperature sufficiently low to form grain boundary cracks as a result of sliding along grain boundaries (which contain steps developed as a result of prior intragranular shear).
Hydrogen “embrittlement” is due to migration of lone hydrogen atoms into the metal where they re-combine in sub-micron sized voids in the metal matrix to form hydrogen molecules. In so doing, they create pressure from inside the cavity where they are located which can increase in vulnerable areas of the metal (e.g., where it has reduced ductility and tensile strength) to the point where the metal develops first micro-cracks and then a large, macro-fracture resulting in castastrophic failure.
Liquid nitrogen storage containers kept dry and free from liquid oxygen accumulation, and which remain stationary, can and do last “indefinitely.” They will require periodic re-hardening of the vacuum, but this is not due to structural failure, but rather is due to outgassing of materials from the reflective/convective barrier wrap and of hydrogen from hydrogen inclusions in the welds. If the units are not man-handled and are well cared for, there is essentially no work-hardening of the welds, or of the structural metal itself, and they may well last for many decades, or even centuries. If the nitrogen gas boil-off were used to create a dry nitrogen sheild around the exterior of the vessels, their lifespan would likely be in the range of many centuries. Work-hardening, hydrogen ingress into the metal from water condensed from the air and corrosion from atmospheric oxygen and water at the neck-tube are the three principal causes of structural cryogenic dewar failure. If the dewar is not moved about, and if water is eliminated from the environment, stainless steel dewars should last indefinitely. I’ve seen dewars in semen storage facilities that are 50 years old and have not yet required rehardening of their vacuum. Conversely, I’ve seen vessels in lab use and used to haul industrial gases fail after a few years, or even a few months of use. TLC is almost everything when it comes to liquid nitrogen dewars.
Probably the best example of how robust ultra-high pressure vessel engineering can be is to look to long range guns on battleships. These tubes are about 2″ in diameter shy of being big enough to hold an average human and can withstand pressures in the range Maxikov is talking about. These “vessels” also have a breech and operate under horrible conditions wih respect to heat and corrosion. And yet, failure is almost unheard of. When failure means the loss of a battle ship, failure is not an option; consider that one turret on a 20th century battleship, exclusive of the guns, cost ~$1.5 million, U.S. These guns were made with mid-1920′s technology and remained in service until the last decade of the past century. Then, there was the Paris-Geschütz (http://en.wikipedia.org/wiki/Paris_Gun) of Krupp, but that’s another story...
Actually, cryogenic vessels do not really fail, in the sense I think you mean, over time—with the notable exception of liquid helium and liquid hydrogen storage vessels. Liquid helium has bizzare effects of metal (in addition to quantum tunneling) causing high strength steel to embrittle over time. It is thoought that this occurs due to the presence of helium in solid solution in the metal subjected to loading, and being present at a temperature sufficiently low to form grain boundary cracks as a result of sliding along grain boundaries (which contain steps developed as a result of prior intragranular shear).
Hydrogen “embrittlement” is due to migration of lone hydrogen atoms into the metal where they re-combine in sub-micron sized voids in the metal matrix to form hydrogen molecules. In so doing, they create pressure from inside the cavity where they are located which can increase in vulnerable areas of the metal (e.g., where it has reduced ductility and tensile strength) to the point where the metal develops first micro-cracks and then a large, macro-fracture resulting in castastrophic failure.
Liquid nitrogen storage containers kept dry and free from liquid oxygen accumulation, and which remain stationary, can and do last “indefinitely.” They will require periodic re-hardening of the vacuum, but this is not due to structural failure, but rather is due to outgassing of materials from the reflective/convective barrier wrap and of hydrogen from hydrogen inclusions in the welds. If the units are not man-handled and are well cared for, there is essentially no work-hardening of the welds, or of the structural metal itself, and they may well last for many decades, or even centuries. If the nitrogen gas boil-off were used to create a dry nitrogen sheild around the exterior of the vessels, their lifespan would likely be in the range of many centuries. Work-hardening, hydrogen ingress into the metal from water condensed from the air and corrosion from atmospheric oxygen and water at the neck-tube are the three principal causes of structural cryogenic dewar failure. If the dewar is not moved about, and if water is eliminated from the environment, stainless steel dewars should last indefinitely. I’ve seen dewars in semen storage facilities that are 50 years old and have not yet required rehardening of their vacuum. Conversely, I’ve seen vessels in lab use and used to haul industrial gases fail after a few years, or even a few months of use. TLC is almost everything when it comes to liquid nitrogen dewars.
Probably the best example of how robust ultra-high pressure vessel engineering can be is to look to long range guns on battleships. These tubes are about 2″ in diameter shy of being big enough to hold an average human and can withstand pressures in the range Maxikov is talking about. These “vessels” also have a breech and operate under horrible conditions wih respect to heat and corrosion. And yet, failure is almost unheard of. When failure means the loss of a battle ship, failure is not an option; consider that one turret on a 20th century battleship, exclusive of the guns, cost ~$1.5 million, U.S. These guns were made with mid-1920′s technology and remained in service until the last decade of the past century. Then, there was the Paris-Geschütz (http://en.wikipedia.org/wiki/Paris_Gun) of Krupp, but that’s another story...