【摘要】 利用Gleebe-3500热模拟试验机首先对GCr15钢在以0.5℃/s的速度降温时的相变点进行了测试,然后模拟了两相区塑性变形(奥氏体+碳化物)和三相区(奥氏体+铁素体+碳化物)塑性变形,通过硬度测试和金相分析,考察了不同温度区间变形和变形量大小对GCr15钢共析转变的影响。认为奥氏体化保温时间的延长,由于碳的溶入增加,会使得共析转变区间的温度范围变窄,从而引起离异共析转变温度发生改变。两相区塑性变形量的大小对碳化物的析出有影响,塑性变形量增加,共析转变过程中碳化物析出趋于充分,导致共析转变后硬度偏低;三相区塑性变形对片状碳化物的形成可能有促进作用,导致微区细珠光体组织,使得共析转变后硬度偏高。更多还原

【Abstract】 The gleeble-3500 testing machine is used to simulate process of plastic deformation in two-phase region of austenite and carbide,and to be done in higher temperature zone of eutectoid transformation range also both for GCr15 steel. Two deformation passes are used in two-phase region and one deformation pass is done in higher temperature zone of eutectoid transformation range after the start and end temperatures of eutectoid transformation of GCr15 are measured respectively by using of the Gleeble-3500 testing machine. The influence on austenitize grains and remained carbide morphology of deformation being conducted are investigated by means of scanning electron microscopy. The hardness of samples is measured with hardness testing machine. The impacting on precipitation,growth as well as morphology of carbides of divorced eutectoid transformation taking place in GCr15 is investigated while plastic deformations are conducted. The results show that the plastic deformation has effect on austenite grain size and amount of remain carbide in austenite. The deformation could help divorced eutectoid transformation,and promote the spheroidization of carbides in GCr15 steel. The hardness of the sample of GCr15 steel is significantly reduced after divorced eutectoid transformation taking place. And the time of the spheroidization of the carbides in GCr15 steel is great shortened.更多还原