testing standard for the determination of the carbon - and sulphur content in steel

摘要

1470811 Steel standard test piece SKF INDUSTRIAL TRADING & DEVELOPMENT CO BV 18 June 1974 [5 March 1974] 27011/74 Addition to 1411722 Heading G1B A process for the determination of the content of one or more of the elements oxygen, nitrogen, carbon and sulphur in steel by comparison with corresponding elements in a standard test piece utilizes as standard test piece a spherical body of steel with a known content of the elements oxygen, nitrogen, carbon and sulphur. The test piece may be made in the same way as a ball-bearing and the polished spherical body may have an outer coating of a noble metal such as gold and also, optionally, an intermediate coating of for example nickel.