3. Multi-phase steels

In the article [M 4 341] for ferritic steels and in the preceding paragraphs for austenitic grades, we concentrated on steels containing a majority constituent. In many cases, the metallurgist uses several of these constituents to develop a more complex microstructure that makes the most of the advantages of each of the constituents. In some cases, this can be traced back to the fundamentals of composite material design. Some examples are described below.