Effect of chemical composition and annealing temperature on microstructure and properties of high strength low alloy steel
In order to further reduce the production cost of high strength low alloy steel(HSLA),the effects of different contents of Nb,Mn and annealing temperature on the microstructure and properties of HSLA steel were studied.The results show that the annealing temperature has no obvious effect on the ferrite grain size of HSLA steel,but the higher annealing temperature is not conducive to the formation of pearlite structure,resulting in a higher content of solid solution C in ferrite,a yield platform in stress-strain curve,and the coarsening behavior of NbC precipitates leads to a decrease in strength of the product.The formation of banded structure in HSLA steel is mainly related to the diffusion behavior of C element,and higher annealing temperature is beneficial to reduce the degree of banded structure.When the mass fraction of Nb increases from 0.014％to 0.021％,the effect of fine grain strengthening and precipitation strengthening is obviously enhanced,and the strength level of HSLA steel is obvi-ously increased.Mn element mainly plays a solid solution strengthening effect in HSLA steel.
chemical compositionannealing temperaturehigh strength low alloy steelmicrostructuremechanical propertieslow cost
NETL
NSTL
万方数据
