Improvements in the Process of Hardening High Speed Steel.

摘要

11,268. Brayshaw, S. N. May 30. Tempering.-In hardening high-speed steel, the article is heated in a bath to a very high temperature, but not sufficiently high to cause sealing of the surface to the deterioration of the steel, and, without being allowed to cool, is removed to a bath at a temperature of above 850‹ C., say 900‹- 950‹ C., and finally quenched in a bath of water, oil, or other liquid at say 100‹ C. The baths may be heated in a furnace such as is described in Specification No. 26,703, A.D. 1903, or otherwise. The article is soaked in each bath sufficiently long to result in an even temperature throughout. Specification No. 12,817, A.D. 1904, is also referred to. According to the Provisional Specification, the temperatures of the two high-temperature baths are stated to be 910‹ C. or thereabouts and 850‹ C. or less, and baths at intermediate temperatures may be employed both in heating and cooling.