STUDY OF MICROSTRUCTURES

— Metallography is the science of evaluating metal structures and is an important field of metallurgy.

— The metallographer must prepare the specimen to obtain a true image of the structure and then exactingly evaluate the structure.

— Examination and study of microstructure of the specimen is required to determine the metallurgical effects of heat-treatment, manufacturing processes (such as welding) etc.

— Trained metallographers are able to evaluate the microscopical appearance of metals and to indicate the past history of the metals so that the advisability of particular metallurgical methods can be predicted.

— Many photomicrographs and sketches of metallic structures are included in the book, because all metallurgical processes have definite effects on the structure of the metals used and the metal­lurgical nature of processes can be studied in terms of these metallographic effects.

— Fig. 42.4 shows microstructures of some important constituents.