Micro alloying in High Strength Low Alloy (HSM) steel is very important role to improve the quality
of those steel formation of precipitation of carbonitride such as Nb(CN) in those niobium containing
steel has a significant influenced on strength. Mechanism of strength improvement due to the existing of
micro alloy the precipitated in hot finishing deformation not fully studied The previous investigated use
relationship between deformation and density of dislocation. HSLA steel containing 0.037% Nb was used
in this research and deformation was performed using compressive plane stress, the relationship between
5 % fraction precipitate, t@__ยข, and maximum stress achieved at a temperature of 9009 C under strain rare of
I sec'l were evaluated. Analysis data results shows that the relationship between 5% fraction and density
of dislocation can be described as, tg,? .,p"'5.
