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低合金钢珠光体→奥氏体相变动力学 总被引:1,自引:0,他引:1
采用DSC法研究了低合金钢组织中珠光体→奥氏体的相变动力学.结果表明:该低合金钢的相变表观激活能为1141.04 kJ/mol,其相变激活能随其相变体积分数的增加而逐渐减小.并在此基础上绘制了相变体积分数与温度之间的关系曲线. 相似文献
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V. N. Antsiferov V. Ya. Bulanov Yu. G. Gurevich A. G. Ivashko M. S. Tsyganova 《Metal Science and Heat Treatment》2005,47(3-4):145-150
A magnetometric complex for studying the decomposition of supercooled austenite is described. The kinetics of phase transformations is studied by the developed method. The kinetic parameters are determined and kinetic diagrams of phase transformations for conditions of stage hardening are plotted. A mathematical model of decomposition of supercooled austenite under conditions of isothermal and stage hardening is developed on the basis of these kinetic parameters and diagrams. An experimental check of adequacy of the models obtained is performed for the whole temperature and time range of the transformation.__________Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 4, pp. 24 – 29, April, 2005. 相似文献
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淬火合金钢中的奥氏体稳定化 总被引:5,自引:0,他引:5
研究了马氏体(M)和贝氏体(B)两相温度区等温淬火组织中的奥氏体稳定化.在一定等温时间内,奥氏体稳定化程度,即残余奥氏体量与等温温度间的关系呈马鞍型曲线.在实验钢中,其谷底值低于用同冷却介质淬火组织中的AR,表明在一定条件下等温停留并不引起残余奥氏体量增多.可利用马鞍型曲线调整AR与M及B的含量配比,获得无变形或强韧性配合最佳的准贝氏体等温淬火工艺.奥氏体稳定化为热稳定化、化学稳定化、相致稳定化和宏观热应力稳定化诸机制的综合作用.马氏体临界点Mc点无特殊物理意义。 相似文献
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采用DSC法研究了变形对低合金钢组织中珠光体→奥氏体相变的影响。结果表明:变形可降低低合金钢的相变温度和相变激活能,缩短相变时间,有利于该低合金钢的相变。 相似文献
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过冷奥氏体等温转变曲线数据库的建立 总被引:5,自引:3,他引:5
本文用三次样条函数描述钢的过冷奥氏体等温转变曲线,在微机上建立了TTT曲线数据库,实现了TTT曲线的数据形式存储与动态调用,操作简单,直观,占用计算机存储空间小,并进一步等温转变动力学公式计算出过冷奥氏体等温转变过程中任意转变量曲线,与手册中的曲线吻合得很好。 相似文献
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V. V. Sagaradze O. V. Fomina T. V. Vikhareva N. V. Kataeva I. G. Kabanova V. A. Zavalishin 《The Physics of Metals and Metallography》2018,119(3):282-288
Features of the decomposition of the ferromagnetic δ ferrite with the formation of nonferromagnetic constituents (γ and σ phases) at temperatures of 900–1200°C in a nitrogen-containing austenitic steel have been determined. The transformation of δ ferrite at high temperatures (1100–1200°C) occurs with the formation of Widmanstäatten austenitic crystals in the ferritic matrix. At lower temperatures (900–1000°C), the transformation of δ ferrite develops by discontinuous decomposition with the formation of colonies of alternating plates of paramagnetic γ and σ phases. In the course of formation of the nonferromagnetic state as a result of the decomposition of δ ferrite at 900–1000°C (for 1 h), a subgrain structure with an increased density of dislocations, which is typical of thermomechanical treatment, is retained in the steel previously strengthened by high-temperature deformation. 相似文献
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综合分析了过冷奥氏体整合系统及其转变贯序。认为过冷奥氏体的转变复杂多变,当以系统整合的方法研究其转变体系。随着过冷度的增加,原子位移方式由扩散位移过渡到界面原子非协同跃迁,再过渡到原子集体协同共格位移。相应的转变贯序为:共析分解→贝氏体相变→马氏体相变。相结构、组织形貌、亚结构等也随之发生演化。 相似文献
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低碳合金结构钢经渗碳或碳氦共渗和淬火后,其渗层组织中存在残余奥氏体,残余奥氏体量过多会使渗层硬度下降,从而影响零件的使用寿命。不同产品对残余奥氏体量的要求量是不同的,可采用相应的热处理工艺进行控制。残余奥氏体量一般采用金相法测定,介绍了检测残余奥氏体的相关标准。 相似文献
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