CONDUCTING PLATES FOR FUEL CELL ELEMENTS

1 - 17 . (canceled)

18 . A method for manufacturing a monopolar or bipolar conducting plate for a fuel cell element, comprising the step of providing at least one alloy having, in percentages by weight:

24.0 to 27.0% nickel;

13.5 to 16.0% chromium;

1.90 to 2.35% titanium;

1.0 to 1.5% molybdenum;

0.10 to 0.50% vanadium;

at most 0.08% carbon;

at most 2.0% manganese;

at most 1.0% silicon;

at most 0.35% aluminium;

at most 0.03% sulphur; and

at most 0.01% boron,

the balance consisting of iron and impurities.

19 . The method of claim 18 , wherein the alloy contains:

24.0 to 25.5% nickel;

14.0 to 16.0% chromium;

2.00 to 2.30% titanium;

1.2 to 1.5% molybdenum;

0.10 to 0.50% vanadium;

at most 0.06% carbon;

at most 2.0% manganese;

at most 0.3% silicon;

at most 0.25% aluminium;

at most 0.01% sulphur; and

at most 0.01% boron, the balance consisting of iron and impurities.

20 . A sheet comprising at least one alloy as defined in claim 18 , wherein said sheet has, at least on one of its faces, an arithmetic mean roughness Sa of 0.12 μm or higher, a maximum height amplitude St of less than 4 μm and, preferably, a developed surface area Sdr of greater than 0.2%.

21 . A process for surfacing a sheet based on an alloy as defined in claim 18 , comprising the following steps in succession:

(a) a semi-finished product chosen from a thin slab or a hot-rolled sheet is cold rolled;

(b) the sheet obtained in step (a) is continuously annealed, at a temperature between 900 and 1200° C. for a time ranging from 10 seconds to 30 minutes, in an oxidizing atmosphere; and

(c) the annealed sheet obtained from step (b) is pickled by bringing it into contact with at least one mineral acid at a temperature of between 40 and 100° C.

22 . The process of claim 21 , which further includes an electrolytic pickling step.

23 . The process of claim 21 , which further includes a step of rinsing, preferably with water, and then of drying the pickled sheet.

24 . A sheet obtainable by the process according to claim 21 .

25 . A process for manufacturing a conducting plate for a fuel cell element, comprising providing the sheet of claim 24 .

26 . A process for manufacturing a conducting plate for a fuel cell element, which comprises the surfacing of a sheet containing at least one alloy, having, in percentages by weight,

24. 0 to 27.0% nickel,

13.5 to 16.0% chromium,

1.90 to 2.35% titanium,

1.0 to 1.5% molybdenum,

0.10 to 0.50% vanadium,

at most 0.08% carbon,

at most 2.0% manganese,

at most 1.0% silicon,

at most 0.35% aluminium,

at most 0.03% sulphur,and

at most 0.01% boron,

the balance consisting of iron and impurities, according to the process defined in claim 21 , wherein the manufacturing process further includes at least the following steps:

said sheet having a thickness of 0.05 to 0.5 mm, in particular 0.1 to 0.2 mm, undergoes a first deformation by means of a first tool in order to obtain a corrugated blank; and

said corrugated blank undergoes a second, tangential deformation by means of a second tool.

27 . The process of claim 26 , wherein the succession of first and second deformations gives the sheet an elongation of at least 25% to 35% relative to the initial length of the sheet.

28 . The process of claim 26 , wherein said sheet has, at least on one of its faces, an arithmetic mean roughness Sa of 0.12 μm or higher, a maximum height amplitude St of less than 4 μm and, preferably, a developed surface area Sdr of greater than 0.2%.

29 . A conducting plate for a fuel cell element, which can be obtained by the process according to claim 26 .

30 . A fuel cell element comprising at least one monopolar or bipolar conducting plate comprising at least one alloy as defined in claim 18 .

31 . A fuel cell element comprising at least one monopolar or bipolar conducting plate comprising a sheet according to claim 20 .

32 . A fuel cell element comprising at least one monopolar or bipolar conducting plate according to claim 29 .

33 . A fuel cell, in particular of the PEMFC (photon exchange membrane fuel cell) type, containing the cell element according to claim 30 .

34 . A method for supplying electricity to a vehicle, such as a motor vehicle, or a telecommunication means, such as a relay antenna or a mobile telephone, comprising providing a fuel cell according to claim 33 .