You can just think of them as any other line on the diagram. Brazing, like soldering, involves introducing a liquid filler metal into a joint without melting the metals that are to be joined. C.J. Smithells, Metals Reference Book, 6th edition, Butterworth, 1984. ASM Metals Handbook, Vol. 8, 8th edition, American Society for Metals, 1975.
Specific gravity is the density of a material divided by the density of water.
A steel plate coated with a ceramic enamel is in a stress-free state at room temperature but is to be heated to an elevated temperature. The strength-limiting flaws in the ceramic are believed to be 100 mm surface flaws.