变形量与变形温度对微合金化耐火钢中针状铁素体形成的影响

Effect of Deformation and Temperature on Formation of Acicular Ferrite in Micro-Alloyed Fire-Resistant Steel

采用OM、TEM和Gleeble热模拟等实验手段,研究了不同变形量与变形温度对微合金化耐火钢中针状铁素体形成的影响.结果表明:随着变形量的增大,在原奥氏体晶界处形核的先共析铁素体尺寸呈现长大的趋势,同时含量增加,而在晶内形核长大的针状铁素体的板条束宽度逐渐减小,但数量也有所下降.真应变为0.2时有利于生成细小的针状铁素体.在奥氏体的未再结晶区对样品进行压缩变形时,压缩过程中产生的位错和析出相等为铁素体形核提供有利位置,可以有效地细化组织.

The effects of deformation and temperature on the formation of acicular ferrite in Mo-Nb-V fire-resistant steels were studied by using OM,TEM and Gleeble simulation test.The results show that with the increase of deformation,the size of ferrite nucleation at grain boundaries of the original austenite as well as its fraction increase,while the lath width of intragranular acicular ferrite gradually reduces and its fraction decreases slightly.The deformation with a true strain of 0.2 is a benefit to the formation of fine acicular ferrite. Dislocation and precipitates generated during the compression deformation in the austenite non-recrystallization region provide more favorable nucleation position, which plays an important role in grain refinement of ferrites.