structure exists only multi-martensite, in which dislocation martensite is dominant.

The morphology and crystallographic analysis of lath martensite in 17CrNiMo6 steel;

Effect of Niobium on Recrystallization of Deformed Lath Martensite Structure of Low Carbon Steel;

Effect of lath martensite on toughness in overheated zone of 10Ni5CrMoV and 12Ni2CrMoVA steels;

The new strength toughen mechanisms, such as super fine Martensitic laths, new strength phases, Laves phase and M 2C carbide, precipitated coherence with Martensitic matrix and the VIM+VAR double vacuum melting with super pureness, super homogenization hotwork, controlled Martensite transformation heat treatment techniques have been investigated.

The results indicate:Being the strengthen phase,the hexagonal Ni3Ti was precipitated on the martensite lath during ageing process,the size of Ni3Ti precipitates and martensite lath were increased with ageing temperature;reverted austenite was precipitated in interlath and intralath,the size and amount of reverted austenite in interlath were increased with aging temperature.

The results show that the steel with 7 μm grains was acquired by thermo-cycle refining treatment,many martensite lath blocks were partitioned into some sub-grains,and a few single lathes were partitioned by some martensite lath packets in new refined grains;compared with the steel treated by 1 050 ℃×1 h,the yield strength of thermo-cycle refined steel w.

The relationship between fracture toughness and notch toughness, tensile ductilities in lath martensite steel has been investigated.