this article on the manufacturing and steel

摘要

1286893 Coating metals HAVEG INDUSTRIES Inc 23 Jan 1970 [27 Jan 1969] 3483/70 Heading C1M A metal article, comprising a base of ferrous metal or other metal having a thermal expansion coefficient similar to that of steel, has a frit composition coated thereon which comprises a mixture of (a) up to 60% by weight of devitrified glass frit, and (b) at least 40% by weight of a corrosion resistant glass frit comprising 63-80% by weight SiO 2 , the glass matrix of the devitrified glass at least partially dissolving in the corrosion resistant glass on firing the frit composition. The metal base is preferably steel. The devitrified particles are preferably of size 0À1-2À0 Á, and comprise 60-85% by weight of the devitrified glass frit, the devitrified frit having been formed by heating the corresponding glass for 1-2 hours at 1000-1600‹ F. The two frits may be milled together and applied to the metal as a slurry in water, the water then being dried and the coating fired at 1400-1700‹ F. The devitrified frit may have the composition (in weight per cent):- Li 2 O 1-25 Al 2 O 3 0-30 SiO 2 60-80 Na 2 O 0- 5 MgO 0- 5 CeO 2 0-10 TiO 2 0- 5 ZrO 2 0- 5 PbO 0- 5 CaO 0-10; while the corrosion-resistant frit may have the composition (weight per cent):- SiO 2 63-80 TiO 2 0- 2 ZrO 2 0- 8 CaO 0- 2 Li 2 O 1- 5 Na 2 O 8-17 K 2 O 0- 7 MgO 0- 2 F 2 0- 3 CoO 0- 1À25 MnO 0- 1À50 NiO 0- 1À50.