PQ600高强度工程机械用钢热轧工艺的研究

Study of Hot Rolling Process of PQ600 High Strength Steel for Engineering Machinery

以PQ600高强度工程机械钢为对象,研究了其热轧工艺对其晶粒及组织的影响。结果表明,随着温度的升高,奥氏体的晶粒度不断增大,而温度升到1170℃以后,保温时间对晶粒度影响较小。当开轧温度为1010℃、变形量小于30%时,PQ600钢中奥氏体出现再结晶,导致晶粒大小不一;当变形量大于30%以后,奥氏体的再结晶较为完全,晶粒度较为均匀。随着变形速率的增大,晶粒尺寸变小,并且在晶界处锯齿状增多。在600℃卷取时,组织中则出现了铁素体和珠光体两种结构。

Taking PQ600 high strength engineering machinery steel as the object, the effects of the hot rolling process on the microstructures and grain sizes were studied. The results show that the grain sizes of the austenite increase with the increasing temperature, and the effect of holding time on the grain sizes is little after the temperature is higher than 1170℃.When the initial rolling temperature is 1010℃ and the deformation is lower than 30%, the austenite in PQ600 steel produces recrystallization to cause the nonuniform grain sizes. But after deformation is higher than 30%, the austenite produces complete recrystallization to cause the uniform grain sizes. The grain sizes decrease with the increasing deformation rate, and the zigzag shape increases in the boundaries. The ferrite and pearlite appear in microstructure when the coiling temperature is 600℃.