US20070267107A1

US20070267107A1 - Stable austenitic stainless steel for hydrogen storage vessels

Info

Publication number: US20070267107A1
Application number: US11/437,546
Authority: US
Inventors: Thorsten Michler
Original assignee: Motors Liquidation Co
Current assignee: Motors Liquidation Co
Priority date: 2006-05-19
Filing date: 2006-05-19
Publication date: 2007-11-22
Also published as: DE102007022611A1

Abstract

An austenitic stainless steel composition is provided that is resistant to embrittlement due to hydrogen and/or low temperature. The steel composition comprises chromium (Cr) at greater than or equal to about 17% by weight; nickel (Ni) at less than or equal to about 13% by weight; nitrogen (N) at greater than 0.16% by weight. The steel is substantially free of molybdenum (Mo). In various embodiments, the steel is used to form a surface of a hydrogen storage vessel that contacts hydrogen and is resistant to hydrogen and low temperature (less than or equal to about −100° C.) embrittlement. Methods of storing hydrogen in vessels made of the hydrogen embrittlement resistant austenitic steel composition are also provided.

Description

FIELD

The present invention relates to corrosion resistant stainless steel, and more particularly to a stable austenitic stainless steel for vessels that store pressurized hydrogen.

BACKGROUND

Fuel cells have been proposed as a power source for automotive vehicles and other applications. Fuel cell systems include a fuel cell stack that produces electrical energy based on a reaction between a hydrogen-containing feed gas and an oxidant feed gas (e.g., oxygen or oxygen-containing air).
Hydrogen storage is a technology critical to fuel cell operation and other kinds of power generating applications. Typical power generating systems include a storage vessel that stores and supplies a hydrogen-containing feed stream to a power plant (e.g., the fuel cell stack) that consumes hydrogen. The hydrogen-containing feed stream can be stored within the storage vessel as a liquid or a compressed gas. In certain applications, the hydrogen-containing feed gas is preferably stored at a temperature of as low as approximately −250° C. to −260° C. as a liquid or alternatively within a temperature range of approximately −100° C. to 100° C. as a pressurized gas.
The handling and containment of hydrogen-containing streams can pose difficulties. Many materials (e.g., high strength ferritic steels) have the potential to be susceptible to hydrogen corrosion, i.e., hydrogen embrittlement. Hydrogen embrittlement is a form of brittle cracking that can occur in various steels and alloys when the materials are exposed to hydrogen.
Further, low temperatures can potentially contribute a brittle fracture behavior of ferritic steels, irrespective of atmospheric conditions. For low temperature applications, such as those where the temperature reaches −100° C. or less, austenitic steels are the most ductile steel. Most austenitic stainless steels have a metastable austenitic structure, meaning the austenitic structure is only stable down to a characteristic temperature, referred to as the “M_s” temperature. When the material is cooled and the increase in free enthalpy exceeds ΔG, parts of the austenitic body face centered structure transform into cubic body centered martensite. The value of ΔG is generally believed to be strongly dependent on the chemical composition of the steel. The formation of martensite contributes to embrittlement of the material, either due to low temperature, exposure to hydrogen, or both. Thus, it is optimal to minimize the formation of martensite. Usually the stability of the austenite is enhanced by increasing the nickel (Ni) content of the steel.
Higher grade materials have generally been used to avoid potential failure of hydrogen storage and handling equipment. For example, higher grades of austenitic stainless steels having relatively high amounts of nickel, chromium, manganese, and/or molybdenum suffer less from hydrogen embrittlement and/or low temperature embrittlement. However, these materials are quite costly, and there is a need for low cost, durable materials for hydrogen storage and handling.

SUMMARY

In various embodiments, the present invention provides a hydrogen storage vessel comprising a surface that comprises an austenitic stainless steel composition comprising chromium (Cr) at greater than or equal to about 17% by weight; nickel (Ni) at less than or equal to about 13% by weight; and nitrogen (N) at greater than 0.16% by weight. The steel composition is preferably substantially free of molybdenum (Mo). Further, the surface is in contact with hydrogen and is preferably resistant to embrittlement to a temperature of about −100° C.
In certain embodiments, the invention provides an austenitic steel composition that is resistant to hydrogen embrittlement. The composition comprises carbon (C) at less than or equal to about 0.07% by weight; nickel (Ni) at less than or equal to about 10.5% by weight; chromium (Cr) at greater than or equal to about 17% by weight; and nitrogen (N) at greater than 0.18% by weight. The composition is preferably substantially free of molybdenum (Mo).
In other embodiments, the invention provides a method for storing hydrogen comprising providing a storage vessel resistant to embrittlement to a temperature of at least about −100° C. The vessel has a surface comprising an austenitic stainless steel composition comprising chromium (Cr) at greater than or equal to about 17% by weight; nickel (Ni) at less than or equal to about 13% by weight; and nitrogen (N) at greater than 0.16% by weight. The composition is preferably substantially molybdenum (Mo) free. The method further comprises transferring a hydrogen-containing stream to the vessel wherein the stream is in contact with the surface. The hydrogen-containing stream is stored in the vessel, where the surface does not experience embrittlement. The hydrogen-containing stream is then stored in the vessel without any embrittlement or associated detrimental effects or damage caused by it.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:

FIG. 1 is a schematic illustration of an exemplary fuel cell system including a hydrogen storage vessel according to the present invention;

FIG. 2 is a schematic illustration of a hydrogen storage vessel according to an embodiment of the present invention; and

FIG. 3 is a schematic illustration of a hydrogen storage vessel according to an alternate embodiment of the present invention.

DETAILED DESCRIPTION

The following description of the preferred embodiments is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. “A” and “an” as used herein indicate “at least one” of the items is present; a plurality of such items may be present, when possible. All percentages indicated are on a weight basis, unless expressly indicated as otherwise.
Generally, stainless steels are divided into three classes based upon the predominant phase constituent of the microstructure, namely: martensitic, ferritic or austenitic. When nickel and chromium are added to steel in sufficient amounts, the crystal structure changes to austenite. Higher nickel content in a stainless steel improves the resistance to hydrogen embrittlement and maintains an austenitic structure, while lower nickel content potentially leads to a metastable structure where the austenite can transform into martensite when exposed to low temperatures. Austenitic stainless steels are steel alloys typically having a centered cubic-lattice structure. Preserving the stability of the austenitic structure is important for obtaining good resistance against embrittlement due to exposure to hydrogen, low temperatures, or both.
Thus, the hydrogen storage vessels of the various embodiments of the invention preferably comprise at least one surface constructed from austenitic stainless steel compositions. Further, as described above, it is preferable that the surface comprising an austenitic structure maintains good resistance against embrittlement. As used herein, “embrittlement” refers to a form of brittle fracture or cracking that occurs in a material when exposed to certain environmental conditions, such as hydrogen and/or low temperatures. Hydrogen embrittlement in particular refers to the deterioration of material properties (especially crack growth rate) due to the influence of hydrogen. In accordance with various embodiments, it is preferred that the steel materials of the invention are resistant to embrittlement at low temperatures. Thus, temperatures at which embrittlement does not occur for compositions of the invention are about 0° C. in some embodiments; about −50° C.; about −100° C.; about −200° C.; and optionally about −250° C. in certain embodiments, depending on the application, as will be described in more detail below. In some applications, the steel materials preferably withstand embrittlement at temperatures as low as about −260° C.
A typical austenitic steel composition has chromium at greater than or equal to about 16% and nickel at greater than or equal to about 8%. Austenitic stainless steels include the 300 series in stainless steel grades. As appreciated by those of skill in the art, varying amounts of elements, such as nickel, chromium, molybdenum, and manganese, can be added and the greater the amounts of these elements that are included, the higher the grade of steel. Of the commercially available austenitic steel compositions, only higher grades (with more expensive alloying elements) are recognized to withstand hydrogen embrittlement.
One exemplary lower grade steel is 316L where carbon (C) is present at less than or equal to 0.03%, chromium (Cr) at about 17%, nickel (Ni) at about 9%, manganese (Mn) at about 2%, and molybdenum (Mo) at about 2.5%. “L” designates low carbon content. 316L is substantially free of nitrogen. It is known that this grade suffers from hydrogen embrittlement at various conditions. A higher grade austenitic stainless steel is Grade 317LMN that has carbon (C) at less than or equal to 0.03%, chromium (Cr) from between about 16.5-18.5%, nickel (Ni) from about 13.5-17.5%, manganese (Mn) from about 1-2%, and molybdenum (Mo) from about 4-5%. In the 317LMN grade, the “M” and “N” designations indicate that the composition contains increased levels of molybdenum and nitrogen respectively. The 317LMN is generally regarded as a stable austenitic steel, which means that the structure remains austenitic regardless of typical industrial temperature conditions.
The degree of embrittlement depends greatly on the strength and composition of the steel. As previously discussed, the addition of chromium, nickel, manganese, and molybdenum to stainless steel compositions is desirable; however, it is also costly. Therefore, traditional stainless steels present a trade-off between cost and resistance to embrittlement and/or good performance through a range of temperatures. Thus, in accordance with preferred embodiments of the present invention, low grade austenitic stainless steel compositions are modified to improve embrittlement resistance. As used herein, “modified” means that a traditional relatively low grade steel composition has increased nitrogen content while having lower amounts of expensive alloying elements, in accordance with the principles of the present invention. The performance in terms of hydrogen embrittlement of the inventive compositions is comparable to higher grade austenitic stainless steels.
Hence, various embodiments of the invention provide an inexpensive, modified lower grade austenitic stainless steel composition that can be used in hydrogen storage applications. Such compositions have increased nitrogen content, which provides a relatively low cost, high performance embrittlement resistant stainless steel. In this manner, less expensive steels (i.e., steels having lower nickel, chromium, and molybdenum content) can be employed, while still having high resistance to hydrogen embrittlement, as well as sufficient toughness (that counteracts embrittlement) at low temperatures.
The increase in nitrogen content, without increasing nickel content, improves the stability of the austenitic structure and resistance to hydrogen embrittlement and/or low temperature. In various embodiments, the nickel content is limited in the compositions of the present invention because of its high cost, as well as the fact that its presence decreases the solubility of nitrogen in the smelting process. Further, in various embodiments, the steel compositions are substantially free of molybdenum. The phrase “substantially free” means that the content of molybdenum is not detectable above an impurity level in the steel composition. As such, the austenitic stainless steel compositions of the present invention have enhanced resistance to embrittlement and increased toughness at lower temperatures without increased cost.
In accordance with various embodiments of the invention, a lower grade inexpensive austenitic stainless steel is thus modified. The most common austenitic steels are the relatively less expensive lower 304 grades, which typically contain about 17-20% chromium, and about 8% nickel. The 304 grades are substantially free of molybdenum. By way of example, an exemplary low Grade 304 austenitic stainless steel has carbon (C) at less than or equal to 0.08%, chromium (Cr) from between about 17-19.5%, nickel (Ni) from about 8-10.5%, manganese (Mn) at less than or equal to about 2%, where the composition has no molybdenum (Mo) added, i.e., the steel is substantially free of Mo. These grades are typical metastable steels meaning that the alloying content of nickel is not generally viewed to be high enough to preserve an austenitic structure at low temperatures.
In the following Table 1, various compositions illustrate the chemical composition of a Standard AISI Grade 317LMN steel (a higher grade austenitic steel), a Standard AISI Grade 304 steel (a lower grade austenitic steel), a Standard AISI Grade 304N (a commercially available lower grade steel with relatively low levels of nitrogen) and two austenitic examples prepared in accordance with the present invention, namely Examples 1 and 2, of two different embodiments of modified Grade 304 steels. The amounts of each element in the steel are expressed as percentages by weight.

TABLE 1

										M_s
Steel	C	Si	Mn	P	S	Cr	Mo	Ni	N	T (° C.) (*)

Grd.	≦0.03	≦0.75	1-2	≦0.045	≦0.03	17-20	4-5	13.5-17.5	0.1-0.2	−305
317LMN
Std.
Grd. 304	≦0.07	≦1	≦2	≦0.045	≦0.03	17-19.5	0	8-10.5	<0.11	+148
Std.
Grd. 304 N	≦0.08	≦1	≦2	≦0.045	≦0.03	18-20	0	8-10.5	0.1-0.16	−60
Std.
Example 1	0.02-0.07	≦1	1-2	≦0.045	≦0.03	18-19.5	0	8-10.5	>0.22	−253
Example 2	≦0.07	≦1	≦2	≦0.045	≦0.03	17-19.5	0	8-10.5	>0.18	−151

(*) Calculated value

As discussed above, the M_stemperature is the temperature at which a martensitic transformation starts, i.e., the austenitic structure transforms to a martensitic structure. In Table 1, the predicted M_stemperature is obtained by calculating the M_stemperature from Equations 1-3 set forth below and using the maximum predicted value from the three equations. In Equations 1-3, “a” is weight % of carbon in the steel composition; “b” is weight % of nickel; “c” is weight % of silicon; “d” is weight % of manganese; “e” is weight % of chromium; “f” is weight % of nickel; “g” is weight % of copper; and “h” is weight % of molybdenum. The equations are as follows:
M _s(° C.)=1305−1665(a+b)−28(c)−33(d)−42(e)−61(f) (Eqn. 1)
M _s(° C.)=1182−1456(a+b)−37(e)−57(f) (Eqn. 2)
M _s(° C.)=502−810(a)−1230(b)−13(d)−30(f)−12(e)−54(g)−46(h) (Eqn. 3)
Equation 1 is provided in Eichelmann, et al., “The Effect of Composition on the Temperature of Spontaneous Transformation of Austenite to Martensite in 18-8-type Stainless Steels,” 45 Transactions of the A.S.M., page 95 (1953). Equation 2 is provided in Monkman, et al., “Computation of M_sfor Stainless Steels,” Metal Progress, page 95 (April 1957). Equation 3 is provided in Pickering, “Physical Metallurgy and the Design of Steels,” Appl. Sci. Pub. Ltd., London, (1978).
Thus, the predicted M_stemperatures indicate whether a steel will withstand embrittlement at certain temperatures. As described above, stability is strongly dependent on the chemical composition of the steel. It is believed that increasing the Ni content appears to cause a great reduction in M_stemperature. However, in accordance with various embodiments of the invention, an increased nitrogen (N) can provide desirable M_stemperatures without needing to increase nickel content or similar expensive elements. In accordance with various embodiments of the invention and as described previously above, it is preferred that the steel compositions are in the austenite phase and that the steel is used in an environment above the M_stemperature to preserve the austenite microstructure in the steel.
In accordance with certain embodiments of the invention illustrated by Example 1, the modified Grade 304 steel having a nitrogen content of greater than about 0.22% is particularly well-suited for storing liquid hydrogen-containing fluids. Liquid hydrogen is typically stored at temperatures below −200° C., and in some cases temperatures that are as low as approximately −250° C. to −260° C. At temperatures at, near, or in certain embodiments below −250° C., the steel of Example 1 will retain its austenitic structure, toughness properties, and resistance to embrittlement, especially in the presence of hydrogen.
In certain embodiments, the Grade 304 modified steel of Example 2 of the invention is useful for compressed gas hydrogen storage applications and includes a nitrogen content of greater than about 0.18%. Gaseous (and pressurized) hydrogen is typically stored within a temperature range of approximately −100° C. to about 100° C.; thus, Example 2 preferably retains its austenitic structure, toughness properties, and resistance to hydrogen embrittlement at least within the range of about −100° C. to about 100° C.
The 317LMN grade has higher molybdenum, nickel, and chromium content that makes it significantly more expensive than the 304 grade steel. The increased amounts of molybdenum, nickel, and chromium enhance embrittlement resistance. Both the modified Grade 304 steels of Examples 1 and 2, according to the present invention, are significantly less expensive than grade 317LMN steel, but are suitable for use in hydrogen storage vessels.
In various embodiments, the present invention provides a hydrogen storage vessel comprising an austenitic stainless steel composition that comprises chromium (Cr) at greater than or equal to about 17% by weight; nickel (Ni) at less than or equal to about 13% by weight; and nitrogen (N) at greater than 0.16% by weight, preferably having nitrogen at greater than about 0.18% by weight, and in some embodiments having nitrogen greater than about 0.22% by weight. In certain embodiments, the nickel is less than or equal to about 12%, more preferably less than 12%, even more preferably less than 11%, and in some embodiments, less than about 10.5%. The steel composition is substantially free of molybdenum (Mo), and is resistant to embrittlement. Preferably the composition has a stable austenitic structure down to temperatures of about −250° C., the temperature of liquid hydrogen. Preferably at least one surface of the vessel is constructed of such a composition. The surface contacts the hydrogen.
In some embodiments, the nitrogen is greater than about 0.18% by weight; optionally greater than about 0.22% by weight. The composition is substantially free of molybdenum (Mo). In some embodiments, the steel composition is resistant to hydrogen embrittlement and consists essentially of: less than or equal to about 0.07% by weight of carbon (C); less than or equal to about 1.0% by weight of silicon (Si); less than or equal to about 2.0% by weight of manganese (Mn); less than or equal to about 0.045% by weight of phosphorous (P); less than or equal to about 0.03% by weight sulfur (S); less than or equal to about 13% by weight nickel (Ni); greater than or equal to about 17% by weight chromium (Cr); greater than 0.16% by weight of nitrogen (N), and the balance iron (Fe) and incidental impurities. In certain embodiments, the nickel is less than or equal to about 12%, more preferably less than 12%, even more preferably less than 11%, and in some embodiments, less than about 10.5%. The composition is resistant to hydrogen embrittlement and preferably has a stable austenitic structure down to about −150° C. The composition is durable, strong, and resistant to hydrogen embrittlement to a typical temperature of gaseous hydrogen for automotive applications.
The steel compositions of the present invention can be used to make hydrogen storage vessels that have operational safety via increased structural stability and capability to withstand potential embrittlement from exposure to the hydrogen-containing fluids. Because of the increased structural stability, the storage vessel can have a thinner wall thickness providing decreased weight and size over storage vessels made from traditional higher grade austenitic stainless steel.
FIG. 1 shows an exemplary fuel cell system 10. The fuel cell system 10 includes a fuel cell stack 12, a hydrogen storage vessel 14 and a compressor 16. In various embodiments, the fuel cell system is in a vehicular or mobile power plant. The fuel cell system 10 further includes a pressure maintaining system 18 and a pressure management system 19. The pressure maintaining system 18 regulates the pressure within the hydrogen storage vessel 14 and operates independent of the fuel cell stack 12 (i.e., regardless of whether the fuel cell stack is ON or OFF). The pressure management system 19 regulates the pressure of the hydrogen provided to the fuel cell stack 12 and operates when the fuel cell stack 12 is ON.
The compressor 16 provides pressurized, oxygen-rich air to a cathode side of the fuel cell stack 12 through a regulator 20. Reactions between the hydrogen and oxygen within the fuel cell stack 12 generate electrical energy that is used to drive a load (not shown). It should be noted that hydrogen provided to the fuel cell stack 12 preferably has a high purity with a minimum amount of undesirable contaminants, such as carbon monoxide. Thus, the hydrogen provided to a fuel cell stack 12 tends to have a relatively high concentration of hydrogen. A control module 22 regulates overall operation of the fuel cell system based on load input and operating parameters of the fuel cell system. The load input indicates the desired electrical energy output from the fuel cell stack 12. For example, in the case of a vehicle, the load input could include a throttle.
FIG. 2 shows an embodiment of the present invention, where the hydrogen storage vessel 14 is in the exemplary form of a tank 30. A passage 32 is provided for permitting ingress and egress of a hydrogen-containing fluid (i.e., liquid or gas). The tank 30 has an interior compartment 34 for storage of the hydrogen-containing fluid. In various embodiments of the present invention, the hydrogen storage vessel 14 can contain a highly pressurized fluid, thus the hydrogen storage vessels, such as tank 30 are preferably designed to be a high pressure storage tank. By “high pressure” it is meant that the hydrogen-containing fluid is stored at pressures up to or exceeding about 70 MPa. In various embodiments, the hydrogen-containing fluid is a pressurized gas. In other embodiments, the hydrogen-containing fluid stream is a liquid. As described above, the gas is preferably stored at a temperature range of about −100° C. to about 100° C. A hydrogen-containing liquid is preferably stored at temperatures as low as −250° C. As was previously described above, the austenitic steel compositions of the present invention having greater than or equal to about 0.18% nitrogen are durable and resistant to hydrogen-embrittlement through the range of temperatures of about −100° C. to about 100° C. Thus, surfaces of the tank 30 that contact the hydrogen-containing fluid stream preferably are constructed of steel materials of the invention that have good durability through these temperature ranges. Likewise, when surfaces of the tank 30 contact hydrogen-containing liquid, the austenitic steel composition preferably can withstand temperatures down to about −250° C. Thus, it is preferred that the steel composition comprises greater than or equal to about 0.22% nitrogen.
Walls 36 of the tank structure form the interior compartment 34 and exterior structure 38 of the tank 30. The portion of the interior compartment 34 that directly contacts the hydrogen-containing stream is preferably fabricated of the modified hydrogen embrittlement resistant austenitic steel of the present invention. As appreciated by one of skill in the art, the designs shown for the hydrogen storage vessels are simplified, and the storage vessel may be in various different forms or shapes, and may include various additional equipment and passages.
In another embodiment, the hydrogen storage vessel is in the form of an alternate configuration of an exemplary and simplified tank 40, as shown in FIG. 3. The tank has an inner liner 42 that forms a continuous surface of an interior storage compartment 44 that contacts and contains the hydrogen-containing fluid. The liner 42 is disposed within the exterior walls 46 of tank 40. A passage 48 for transporting hydrogen-containing streams to and from the interior storage compartment 44 is provided. In the present embodiment, the austenitic steel composition of the present invention forms the liner 42. However, the exterior walls 46 of tank 40 may be fabricated from other less expensive materials. The material that contacts and contains the hydrogen-containing stream is durable and resistant to hydrogen embrittlement; however the remainder of the tank 40 structure can be fabricated from other materials to realize a cost savings, an increase in strength and durability, and/or weight reduction. Further, in certain embodiments, an insulator material 50 can be provided in an intermediate region between the liner 42 and the exterior walls 46 to maintain the desired storage temperatures for the hydrogen fluid.
In various embodiments, a method is provided for storing and/or containing hydrogen. The method comprises providing a storage vessel having a surface that is resistant to embrittlement to a temperature of at least about −100° C. As appreciated by one of skill in the art, the surface of the vessel that is resistant to hydrogen embrittlement can comprise any of the various embodiments of austenitic stainless steel compositions according to the present invention, as described above. In one embodiment, the vessel has a surface comprising an austenitic stainless steel composition comprising chromium (Cr) at greater than or equal to about 17% by weight; nickel (Ni) at less than or equal to about 13% by weight; and nitrogen (N) at greater than 0.16% by weight. The composition is preferably substantially molybdenum (Mo) free.
The method further comprises transferring a hydrogen-containing stream to the vessel wherein the stream is in contact with the surface. In certain embodiments, the stream is pressurized prior to or during the transferring. The hydrogen-containing stream is stored in the vessel and the surface(s) of the vessel that contact the stream do not experience embrittlement. The hydrogen-containing stream is then stored in the vessel without any embrittlement or associated detrimental effects or damage caused by it.
Steels are typically made in furnaces, such as basic oxygen process furnaces (BOF), open hearth furnaces (OHF), and electric arc furnaces (EAF). Most steel is now made in integrated steel plants using a version of the BOF process or in specialty steel plants that use EAF process. In an exemplary BOF process, hot liquid blast furnace metal, scrap, and fluxes are charged to a converter (furnace). Nitrogen and other alloying elements are added at the desired concentrations. Nitrogen can be introduced into the steel composition by charging the furnace with chromium nitride (CrN), manganese nitride (MnN), or mixtures thereof, for example. A lance is lowered into the converter and high-pressure oxygen is injected. The oxygen combines with and removes the impurities in the charge. These impurities consist of carbon as gaseous carbon monoxide, and silicon, manganese, phosphorus and some iron as liquid oxides, which combine with lime and/or dolomite to form the steel slag. At the end of the refining operation, the liquid steel is poured into a ladle while the steel slag is retained in the vessel and subsequently tapped into a separate slag pot. In this manner, steel compositions of the invention can be made to have the desired elemental content, including the desired nitrogen content.
The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.

Claims

1. A hydrogen storage vessel comprising a surface that comprises an austenitic stainless steel composition comprising:

chromium (Cr) at greater than or equal to about 17% by weight;

nickel (Ni) at less than or equal to about 13% by weight; and

nitrogen (N) at greater than 0.16% by weight, wherein the steel composition is substantially free of molybdenum (Mo), and wherein the surface is in contact with hydrogen and is resistant to embrittlement to a temperature of about −100° C.

2. The vessel of claim 1, wherein the composition comprises nitrogen (N) at greater than or equal to about 0.18% by weight.

3. The vessel of claim 2, wherein the composition comprises nickel (Ni) at less than or equal to about 10.5% by weight.

4. The vessel of claim 1, wherein the composition comprises nitrogen (N) at greater than or equal to about 0.22% by weight.

5. The vessel of claim 4, wherein the composition is resistant to embrittlement to a temperature of about −250° C.

6. The vessel of claim 1, wherein the composition is resistant to hydrogen embrittlement at temperatures in the range of about −100° C. to about 100° C.

7. The vessel of claim 1, wherein the vessel is charged with a pressurized hydrogen-containing gas, and the surface is in contact with said pressurized hydrogen-containing gas.

8. The vessel of claim 1, wherein the vessel is a high pressure storage tank.

9. The vessel of claim 1, wherein the surface forms a liner that contains the hydrogen.

10. A vehicular power plant comprising the vessel of claim 1, wherein the hydrogen storage vessel stores hydrogen that is provided as a fuel to the vehicular power plant.

11. An austenitic steel composition that is resistant to hydrogen-embrittlement comprising:

carbon (C) at less than or equal to about 0.07% by weight;

nickel (Ni) at less than or equal to about 10.5% by weight;

chromium (Cr) at greater than or equal to about 17% by weight;

nitrogen (N) at greater than 0.18% by weight; and

wherein said composition is substantially free of molybdenum (Mo).

12. The composition of claim 11, wherein the composition further comprises

silicon (Si) at less than or equal to about 1.0% by weight;

manganese (Mn) at less than or equal to about 2.0% by weight;

phosphorus (P) at less than or equal to about 0.045% by weight;

sulfur (S) at less than or equal to about 0.03% by weight; and

the balance iron (Fe) and incidental impurities.

13. The composition of claim 11 wherein said composition comprises nitrogen (N) at greater than or equal to about 0.22% by weight.

14. A method for storing hydrogen comprising:

a. providing a storage vessel resistant to embrittlement to a temperature of at least about −100° C., said vessel having a surface comprising an austenitic stainless steel composition comprising chromium (Cr) at greater than or equal to about 17% by weight; nickel (Ni) at less than or equal to about 13% by weight; and nitrogen (N) at greater than 0.16% by weight; wherein said composition is substantially molybdenum (Mo) free;

b. transferring a hydrogen-containing stream to the vessel wherein said stream is in contact with the surface; and

c. storing said hydrogen-containing stream in said vessel, wherein the surface does not experience embrittlement.

15. The method of claim 14, wherein said austenitic stainless steel composition comprises nitrogen (N) at greater than about 0.18%.

16. The method of claim 14, wherein said austenitic stainless steel composition comprises nitrogen at greater than about 0.22% by weight.

17. The method of claim 14, wherein said vessel is resistant to embrittlement to a temperature of at least about −250° C.