40CrNiMo钢的热变形特征及变形抗力模型
２０１８年７月第４２卷第７期 Vol．４２No．７Jul．２０１８
DOI :１０．１１９７３/j x g ccl２０１８０７０１２
收稿日期:２０１７-０８-０３;修订日期:２０１８-０６-０６
作者简介:李科元(１９９１－),男,陕西咸阳人,硕士研究生通信作者(导师):王敬忠副教授４０CrNiMo 钢的热变形特征及变形抗力模型
李科元,王敬忠,杜忠泽,王庆娟,刘阿娇
(西安建筑科技大学冶金工程学院,西安７１００５５)
摘 要:采用Gleeble -３５００型热模拟试验机对４０CrNiMo 钢进行了单道次热压缩试验,
得到了其在应变速率０．１~５０s －１二变形温度８００~１１００?下的应力-应变曲线,观察了变形后的显微组织并分析了热变形特征;建立了该钢的变形抗力模型并进行了试验验证.结果表明:较高的变形温度
或较低的应变速率更有利于４０CrNiMo 钢的完全动态再结晶;变形温度为８００?时,应变速率增大
使动态再结晶晶粒增多;应变速率为１０s －１条件下,当变形温度由８００?升至９００?时,动态再结
晶晶粒增多,变形温度为１０００?时,４０CrNiMo 钢发生了完全动态再结晶,
变形温度为１１００?时,动态再结晶晶粒长大;计算得到４０CrNiMo 钢的动态再结晶激活能为３２２．５３kJ mol －１;
由周纪华-管克智模型计算得到的变形抗力与试验值的平均相对误差为４．８２％,
模拟精度较高.关键词:４０CrNiMo 钢;
流变应力;变形抗力;显微组织中图分类号:TG１４２ 文献标志码:A 文章编号:１０００-３７３８(２０１８)０７-００５７-０５Hot Deformation Characteristics and Deformation Resistance Model of ４０CrNiMo Steel
LI Ke y uan ,WANG Jin g zhon g ,DU Zhon g ze ,WANG Q in gj uan ,LIU A j iao
(School of Metallur g ical En g ineerin g ,Xi ?an Universit y of Architecture and Technolo gy ,Xi ?an ７１００５５,China )Abstract :The stress -strain curves of ４０CrNiMo steel at the strain rates of ０．１－５０s －１and deformation
tem p eratures of ８００－１１００?were obtained b y sin g le p ass hot com p ression ex p eriment on the Gleeble -３５００thermo -simulation machine．The microstructure after deformation was observed and the hot deformation
characteristics of ４０CrNiMo steel were anal y zed．The deformation resistance model of the steel was established and verified b y ex p eriments．The results show that the relativel y hi g h deformation tem p erature or relativel y small strain
rate were favorable for the com p lete d y namic recr y stallization of ４０CrNiMo steel．When the deformation tem p erature was ８００?,the amount of d y namic recr y stallization g rains increased with the increase of the strain rate．When the
strain rate was １０s －１,the amount of d y namic recr y stallization g rains increased when the deformation tem p erature increased from ８００?to ９００?;the com p lete d y namic recr y stallization of ４０CrNiMo steel occured at the
defermation tem p erature of １０００?;the d y namic recr y stallization g rains g rew u p at the deformation tem p erature of
１１００?．The calculated d y namic recr y stallization activation ener gy of ４０CrNiMo steel was ３２２．５３kJ mol －１．The avera g e relative error between deformation resistance calculated b y ZH OU Jihua -GUAN Kezhi model and ex p erimental values was ４．８２％,indicatin g a relativel y hi g h accurac y ．Ke y words :４０CrNiMo steel ;flow stress ;deformation resistance ;microstructure
０ 引 言４０CrNiMo 钢是一种中碳Cr -Ni -Mo 系钢,
其综合力学性能较好二淬透性高二抗过热稳定性强二
韧性好二生产工艺较简单,广泛应用于制造受冲击载荷较高二断面尺寸较大的零部件,如汽轮机和喷
气式客机的起落架二大型发电机转子二喷气涡轮机
轴及其他结构部件等[１-２].变形抗力是材料在高温下的基本属性,受变形温度二变形程度二应变速率和材料化学成分的影响,同时也是材料显微组
织演变的综合反映[３],因此研究材料的热变形特征是非常重要的.热变形过程中发生的动态再结晶二动态回复和超塑性行为均有利于材料的加工,
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