Phases present in a hypereutectoid steel slowly cooled from the AUS phase:

Pearlite is not a phase, but two phases ­ CM + FE

Small sections of a large cast iron casting must be severely cold-worked after casting. Which of the following must be done:

The idea here is that the graphite must be spherical in shape

the casting must be annealed before working ­ does not make graphite particles spherical

the casting must be slowly cooled to avoid MAR formation - does not make graphite particles spherical

the molten metal must be inoculated with Mg - makes graphite particles spherical

UNDER EQUILIBRIUM CONDITIONS, P can form at any temperature in the range 723° C down to room temperature ­ under equilibrium conditions, all AUS must transform at 723°C ­ see phase diagram (no AUS exists below 723°C)

tempering MAR for long periods at high tempering temperatures causes proeutectoid FE to form ­ proeutectoid FE only comes from AUS ­ also, the word proeutectoid means before the eutectoid or pearlite formation. There is no no pearlite in MAR

AUS can not be formed by heating which of the following to a sufficiently high temperature:

MAR ­ heat a steel in ANY condition to >723°C and it will form AUS

a 3% C cast iron ­ in fact, heat any mixture of FE + CM and it will form AUS see phase diagram)

pure CM ­ on the other hand, heat pure CM and it forms --- pure CM! (see phase diagram)

WC tools are: processed by POWDER METALLURGY techniques. They are not steels.

formed by heating a mixture of WC and Co to a temperature high enough to melt the Co, which flows around the WC and holds it together when cooled ­ no melting, only solid state diffusion