The Morphology of Microstructure Composed of Lath Martensites in Steels

Metallographic characteristics of lath martensite stTllcture were investigated ill detail in pure Fe-C alloys and plain carbon commercial steels containing liP to O.B % C, Fe-0.2 % C-X alloys (X: about 1% ifMn, Si, i, Cr or Mo) and an 1B% Ni maraging steel. In the Fc-C alloys and steels, both jJackets and blocks are clearly observed in the lath martensite structure containing less than about 0.2 ";o C. With increase in carbon content from 0.2 % to 0.5 % C, the blocks are gradually extinguished and finally become difficult to observe, although the packets are still fo und.