| 摘要 |
525,655. Lubricants. METALLGES. AKT.- GES. Feb. 24, 1939, Nos. 6221, 6222 and 6223. Convention dates, March 4, 1938, March 18, 1938 and June 1, 1938. [Class 91] [Also in Group XXII] In machining metals a fluid cutting medium which forms a skin on the surface of the metal in the vicinity of the cut is used without oils. Suitable media are those used for phosphatizing processes such as Parkerising and Bonderising. Examples are : (1) a solution containing, per litre, 19 grms. of Zn, 24.5 grms. of NO 3 , 23.8 grms. of P 2 O 5 or 4.4 grms. of Mn and 15.5 grms. of P 2 O 5 . (2) Aqueous solutions of chromic acid and chromates, or such solutions containing free phosphoric acid or phosphates ; suitable solutions consist of 4.4 grms. of Zn, 13.1 grms. of P 2 O 5 , and 3.4 grms. of CrO 3 per litre, or 3.5 grms. of Na, 12.3 grms. of P 2 O 5 , and 3.16 grms. of CrO 3 per litre. Solutions containing chromium also protect the work and the machine tool parts from rust. |
