Determination of Upper Limit Temperature of Strain-induced Transformation of Low Carbon Steels
Determination of Upper Limit Temperature of Strain-induced Transformation of Low Carbon Steels
复制标题
低碳钢应变诱导相变上限温度的确定
DOI：
10.2355/isijinternational.42.1119
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发表时间：
2002
期刊：
影响因子：
--
通讯作者：
Guo
中科院分区：
文献类型：
--
作者：
L. Du;Cai;H. Ding;Xianghua Liu;Guo
在Gleeble 1500热模拟试验机上进行了喷水淬火和落水淬火两种淬火方式的试验，结果表明喷水淬火试样的冷却速度分布不均匀，落水淬火试样的冷却速度分布均匀。确定了防止铁素体析出的临界冷却速度，确定了喷水淬火试样中组织冻结到室温时的组织观察位置，并利用该方法确定了试验材料的Δ d3约为830°C。采用二次淬火方法，进行了不同温度下的单道次变形实验，显微组织分析表明，随着变形温度的降低，铁素体形态在800°C左右由魏氏组织和他晶组织转变为等轴组织。结合在不同温度下变形后冷却过程中测得的膨胀-温度曲线，确定了测试材料的A d3也约为830°C。
Two quenching methods were applied in the experiments carried out on Gleeble 1 500 thermomechanical simulator: (1) spurting water; (2) making the samples drop into water, and the cooling rate distributed un-uniformly in the samples quenched by the former and uniformly by the latter. The critical cooling rate of preventing ferrite precipitation was determined, and the microstructure observation position in which the microstructure could be frozen to room temperature in the samples quenched by spurting water was also determined, and using this method the A d3 was determined to be about 830°C for tested materials. Using second quenching method, single-pass deformation experiments at different temperatures were carried out, and the microstructure analysis indicates that, as the deformation temperature decreased, the ferrite morphology changed from Widmanstatten and allotriomorphs to equiaxed at about 800°C. Combining the dilation-temperature curves measured during cooling process after deformation at different temperatures, the A d3 was determined to be also about 830°C for tested materials.