ENAMEL FRITS FOR ACID-RESISTANT ONE-COAT ENAMELLINGS ON UNPICKLED STEELS

摘要

An enamel frit for producing an acid-resistantenamelled steel in a single coating comprising at leastabout 40 % of silicon atoms, 50 % of silicon atoms andboron atoms, where the proportion of the boron atomsshould not fall below 6.5 %, 63 % of silicon atoms,boron atoms and sodium atoms, where the proportion ofthe sodium atoms should not fall below 7.5 %, eachrelative to the overall total of the non-oxygen atomsin the frit, the proportion of the remaining non-oxygenatoms being less than about 37 %, and 1.0 to 1.2 % ofcobalt atoms. In addition, there are (1) x fluorineatoms with 1 % ? x ?11 % and at least y lithium atomsand at most 2 y lithium atoms with y = (15/x) + 5 beingpresent, the proportion of lithium atoms being fromabout 6.3 % to 20 % relative to the overall total of thenon-oxygen atoms in the frit, or (2) y lithium atomswith 6.3 X ? y ?20 % and at least x fluorine atoms andat most 2 x fluorine atoms with x = 15/(y-5) beingpresent, the proportion of fluorine atoms being fromabout 1 % to 11 % relative to the overall total of thenon-oxygen atoms in the frit.