Study On The Strengthening Mechanism Of Alloying Elements For Ultra-high Strength Low-alloy Steels By EET

Ultra-high strength of low-alloy steels is widely used,due to the low content of alloy elements and low cost.At present through the experiment to improve the mechanical behavior of ultra-high strength of low-alloy steel mainly adopt the method of change the content of alloy elements.Calculated from electron level to analyze the reinforce mechanism of alloy elements on ultra-high strength of low-alloy steel,can reduce the blindness of the experiment from a certain extent.Mechanical properties of three kinds of ultra-high strength of low-alloy steels were calculated,the calculation results with the experimental value of relative error less than10%,illustrated the feasibility of EET calculations.And calculated the valence electron structure parameters of each structural unit of ultra-high strength of low-alloy steels were calculated under the condition of different alloy element content,and analyzed the carbon and alloy elements influence on the mechanical properties of ultra-high strength of low-alloy steels in the electronic level.The results show that:with the increase of content of C would improve the n’_A of structure unit and△ρ’of the phase interface,thus to further strengthen the matrix;The n’_A of structural unit and△ρ’of phase interface(exceptα’-Fe/α’-Fe-C-Mo)which containing Mo、Ni、Cr element relative to the other elements are larger,they make greater contribution to the strengthening effect of ultra-high strength of low-alloy steels,thereinto,the n’_Aand△ρ’of structure unit and phase interface which containing Mo is the biggest,relative to the Mo、Cr element,Ni element can more effectively improve the shock resistance of steel;Phase transition temperature of low temperature tempering of structural unit which containing Mn、Cu element is low,can effectively improve the elongation of steel after tempering,but on the improvement of impact energy relative to the Mn element Cu element is smaller,can use the Mn element instead of Cu element;Relative to other alloying elements the most strong bond energy ofα’-Fe-C-Si andα’-Fe-C-V is larger,therefore,Si and V can improve the tempering stability of Ultra-high strength of low-alloy steels.