Porcelain (vitreous) enamel and industrial enamelling processes it was the authors deliberate intention not to substantially change the original book but to update and expand it with the numerous developments over the past 50 years. Using metallic pigments, a low-temperature enamel was invented that fires at about 1,000°f (538°c) on aluminum or aluminized steel. a high-temperature steel cover coat firing about 1,500°f (816°c) has also been developed with similar properties to the cover coats tested. Steel at a temperature of over 800ºc. the most im-portant component of enamel is quartz. as the melt-ing point of quartz is very high (1620ºc), the melting point is lowered by adding basic metal oxides as well as sodium- and potassium oxides to it. a good bonding of the enamel to the steel is ensured by adding nickel- 8 user manual – steel for enamelling and enamelled steel – arcelormittal 2.1 the colour of enamel depends on the type of colouring agent, the composition of enamel enamel is a glass obtained by fusion at high temperature between 1000°c and 1300°c. its main constituent is silica, sio2, which is the most abundant mineral in the earth’s crust.