Experimental investigation of temperature-dependent interfacial heat transfer mechanism with spray quenching for 22MnB5 steel
Experimental investigation of temperature-dependent interfacial heat transfer mechanism with spray quenching for 22MnB5 steel
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DOI：
10.1016/j.applthermaleng.2017.04.029
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发表时间：
2017-07
影响因子：
6.4
通讯作者：
L. Ying;Tianhan Gao;M. Dai;Y. Yang;P. Hu
中科院分区：
文献类型：
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作者：
L. Ying;Tianhan Gao;M. Dai;Y. Yang;P. Hu
通过控制工艺参数，可热处理高强度22 MnB 5钢经高压喷雾淬火后，力学性能得到明显改善。热态零件与流体介质的接触是一个复杂的两相流淬火过程，直接影响其组织和力学性能。研究了22 MnB 5高强钢喷雾淬火过程中界面传热系数随温度变化规律的影响因素。基于单点喷雾实验平台，分析了流场和沸腾阶段对喷雾效果的影响。采用Beck非线性估计法计算空白与液体介质之间的液-固接触T-IHTC。讨论了不同工艺因素，包括喷射空气和水的压力、喷射高度、初始淬火温度和氧化层的影响。结果表明，T-IHTC峰值出现在核态沸腾阶段，T-IHTC与喷射压力呈幂函数正相关，与初始淬冷温度和喷雾高度呈负相关。此外，表面氧化层对T-IHTC也有显著影响，它阻碍了钢与流体介质的接触，导致传热效率减弱。
The mechanical properties of heat treatable high strength 22MnB5 steel will become much more excellent after high pressure spray quenching through controlling process parameters. The contact between hot parts and fluid medium is a complex two-phase flow quenching process, which can affect the microstructure and mechanical properties directly. A main objective of this paper is to investigate the influence factors on temperature-dependent interfacial heat transfer coefficient (T-IHTC) law during spray quenching process for 22MnB5 high strength steel. The impact of flow field and boiling stages were analyzed based on single-point spray experimental platform. The Beck’s non-linear estimation method was used to calculate the fluid-solid contact T-IHTC between blank and fluid medium. The influence of different process factors, including injection air and water pressure, spray height, initial quenching temperature and oxide layer, were discussed. The results showed that the peak of T-IHTC appears in nucleate boiling stage, the T-IHTC correlates highly with injection pressure by a positive power function, and inverse correlation with the initial quenching temperature and the spray height. In addition, surface oxide layer also has a significant impact on T-IHTC, which impedes the contact between steel and fluid medium, leads to the weakening of heat transfer efficiency.