合金元素及热处理工艺对1000MPa级TRIP钢性能的影响

为了获得强度高(1 000 MPa)、塑性好的相变诱发塑性(TRIP)钢,通过拉伸实验、SEM、TEM和XRD等方法研究了合金元素及贝氏体等温温度对实验钢的影响.结果表明:随着等温温度的升高,强度先下降后上升.延伸率与强塑积都随着温度的升高先上升,在400℃出现峰值后下降.等温温度低于320℃或高于480℃时,抗拉强度最高,达到1 000 MPa以上,强塑积达到22 080 MPa.%;400℃等温时,延伸率和强塑积最高,分别达到31%和27 150 MPa.%.Al部分取代Si后,实验钢强度下降.再加入0.5%Cu,强度明显上升,延伸率下降,强塑积达到25 085 MPa.%.说明在一定热处...

Effects of Alloying Elements and Heat Treatment on Mechanical Properties of 1 000 MPa Grade TRIP Steels

To achieve the objective of both high strength and plasticity in TRIP(transformation induced plasticity) steels,the influences of alloying elements and isothermal treatment temperatures on mechanical properties were investigated by tensile test,SEM,TEM and XRD techniques.The results indicated that with the isothermal treatment temperature increasing,the yield strength and the tensile strength decrease initially then increase.Nevertheless,the elongation and the combination of strength and elongation follow the countrary trend of the strength.The maximum tensile strength of over 1 000 MPa and combination of strength and elongation of 22 080 MPa·% are achieved when the bainite isothermal temperature is below 320 ℃ or above 480 ℃.When the isothermal treatment temperature is within the bainite region of 400 ℃,the highest elongation and combination of strength and elongation are 31% and 27 150 MPa·%,respectively.If Si is substituted partially by Al,the tensile strength decreases.As 0.5% copper is added,the tensile strength increases while the total elongation value decreases.The combination of strength and elongation under such a condition is 25 085 MPa·%.Thus,under certain heat treatment process,high tensile strength and elongation of steels containing proper alloying elements can be obtained.