不同受热条件下高延性冷轧带肋钢筋的力学性能和晶粒度

Mechanical properties and grain size of high ductility cold-rolled ribbed steel bar under different heating conditions

为了判断建筑物失火后墙体内部冷轧钢筋能否继续满足使用要求，本文研究了高延性冷轧带肋钢筋的力学性能、组织及晶粒度与受热条件之间的关系，得出了以下结论：在500℃以下，该钢筋的抗拉强度、屈服强度及基体组织变化不大；在500～600℃之间，钢筋的力学性能及内部组织受温度影响特别显著，抗拉强度和屈服强度急剧下降，并出现了再结晶；当温度超过600℃后，抗拉强度、屈服强度基本趋于稳定，并出现了大量再结晶晶粒，形变织构基本消失。

In order to determine if the properties of the cold-rolled steel in buildings after the fire can still meet the service requirements , the high ductility of cold-rolled ribbed steel mechanical properties , microstructure and grain size and the relationship between the heating conditions were investigated .The results shows that the tensile strength , yield strength and the microstructure of the matrix of the tested steel change a little when the heating temperature is below 500℃;mechanical properties of the tested steel and the microstructure are significantly affected by temperature between 500-600 ℃, the tensile strength and yield strength decreasing sharply , and recrystallization appears , when the temperature exceeds 600 ℃, the tensile strength , yield strength basically tends to be stable , a large number of recrystallized grains form in the microstructure and the deformation texture disappeares .