PROCEDURE FOR DETERMINATION OF HYDROGEN CONTENT IN ALUMINIUM ALLOYS Russian patent published in 2011 - IPC G01N25/38 

FIELD: metallurgy.

SUBSTANCE: procedure consists in melt sampling, in manufacture of cylinder specimen and in determination of amount of hydrogen contained in melt. Melt sampling is performed with casting a portion of liquid metal into a metal mould of cylinder cross section and in successive cooling at rate of 3-6°C/sec. Also, the specimen is manufactured from a cast sample by circular mechanical treatment removing surface layer of metal of thickness not less, than 0.12 H from gate and bottom parts, where H is height of a cast sample. On other surfaces there is removed a layer of metal of thickness, not less, than 0.05 D, where D is diametre of the cast sample; on all treated surfaces of the specimen there is obtained parameter of roughness Ra<1 mcm. Content of hydrogen is determined after heating mechanically treated specimen in vacuum to temperature 680-720°C. Further, it is melted at the moment of occurring the first gas bubbles of hydrogen on surface of melt with consideration of measured values of melt temperature and pressure above melt metal.

EFFECT: raised accuracy.

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