| 摘要 |
600,850. Etching. UNITED CHROMIUM, Inc. March 14, 1947, Nos. 7221 and 7222. Convention dates, Nov. 19, 1943, and July 18, 1944. Drawings to Specification. [Class 100(ii)] [Also in Group XXXVI] Relates to the production of chromium surfaces having mud-crack type markings with intervening plateau areas by electrodeposition of chromium followed by etching and consists in the control of the plating conditions so that the markings developed by the etching may be of a desired average plateau size (see Group XXXVI). The etching treatment may be as described in Specification 600,818. |
