Analyze of Metallic Powders on Content of the Oxygen, Nitrogen, Hydrogen Admixture

Abstract

Properties of compact metals depend, in base, from oxygen, nitrogen and hydrogen conсentrations in their volumes. Powders have peculiarities, which distinguish from compact metals. Literature review on methods of determination oxygen, nitrogen and hydrogen of content in metallic powders. Main method of control of the gaseous admixture in metallic powders is method of the restoration melting of analytical metal in carring gas flow (helium, argon, nitrogen) in graphite crucible in impulse condition. Principal peculiarities and advantages of this method are enumerated. Examples of analysis of real objects — powders of pure metals and alloys (iron, chromium, manganese, ferromanganese, ferrosilicon, nickel alloys) is given. Samples preparation is the most difficult operation in the time of analyses of metallic powders (selection, manufacturing, drying, preservation, transport of analytical samples). Problems of calibration of the methods and analysers by standard samples are considerd. Problems of creation of the standard samples from powder metals with known oxygen, nitrogen and hydrogen concentration are considerd. Lack of the standard samples of metallic powders on gaseous admixtures (oxygen, nitogen, hydrogen) are showed. Method of determination oxygen, nitrogen and hydrogen contents in highalloyed nickel — tempe­rature of heating on graphite crucible, time, mass of analytical sample — are created. Materials for creation of the standard samples of powder metals with certain concetration gaseous admixture with good prospects — highalloyed nickel with low oxygen, nitrogen and hydrogen concentrations — are proposed.