ZHENG Lei
,
YUAN Ze-xi
,
SONG Shen-hua
,
XI Tian-hui
,
WANG Qian
钢铁研究学报(英文版)
Austenite grain sizes in the heat affected zone (HAZ) of a high heat input welded Zr-Ti bearing microalloyed steel are measured under different welding conditions simulated by a Gleeble-1500 thermal-mechanical simulator. The austenite grain growth is divided into two regimes in terms of temperature. When the temperature is lower than 1250 ℃ where the pinning effect of precipitates is strong, the austenite grain size increases slowly with increasing peak temperature, but it increases drastically when the temperature is higher than 1250 ℃ where the pinning effect of precipitates is weak. Based on the experimental measurements, an analytical model for predicting the austenite grain size in the heat affected zone is derived. Model predictions indicate that the initial grain size has little effect on the final one, and the grain growth depends mainly on heat input and peak temperature as well as growth activation energy and exponent. With the use of the model, the width of coarse grained heat affected zone (CGHAZ) for a thick plate is predicted.
关键词:
welding
,
high heat input
,
microstructure
彭宁琦
,
唐广波
,
刘正东
,
吴秀月
金属学报
doi:10.3321/j.issn:0412-1961.2009.03.013
根据Aaronson提出的超组元模型,借助Ae3的实验数据,提出了修正的置换型元素Xi(Xi=Si,Mn,Ni,Co,Mo,Al,Cu,Cr)的Zener两参数,修正中考虑了合金元素间的交互作用.修正后的超组元模型的预测精度明显改善:Ae3计算值与实验值的标准差为10.8℃,与Thermo-Calc计算值的标准差为2.35℃;Ae1计算值与实验值的标准差为6.8℃.按照马氏体相变热力学的计算方法,采用经修正的参数计算了马氏体相变开始温度Ms,提高了Ms点的预测精度,计算值与实验值的标准差为25.3℃.
关键词:
相变
,
热力学
,
超组元模型
,
相变平衡温度
盛广
,
杨志刚
金属学报
根据Fe--C--Xi合金系的正平衡和准平衡热力学模型，推导了简便的奥氏体--铁素体相变驱动力计算解析式。根据公式, 代入合金原始成分和Ae3温度, 即可准确计算正平衡和准平衡模式下的奥氏体--铁素体相变驱动力。采用这一方法计算了Fe--C--Mn--Si--Ni--Cr--Mo--Cu八元系的正平衡和准平衡奥氏体--铁素体相变驱动力。
关键词:
正平衡
,
null
,
null
,
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