Commercially pure Ti (CP‐Ti) was heat treated at 1273 K (1000°C), which was higher than β‐transus temperature, followed by water quenching. The dwell time at 1000°C was changed from 1 to 240 h. The heat treatment at 1000°C resulted in α grain coarsening, whereas martensitic transformation occurred due to the rapid cooling from β phase. The hardness increased by the martensitic transformation, where higher hardness was achieved by longer dwell time at 1000°C. However, the fatigue strengths of the heat‐treated CP‐Ti were lower than that of the as‐received one. The fatigue strength of the specimen with the shortest dwell time of 1 h was the lowest among the heat‐treated samples with different dwell times. Untransformed coarse α grains were seen in the heat‐treated specimens, which resulted in the lower fatigue crack initiation resistance and fatigue strength than the as‐received specimen.

中文翻译：

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β-转变温度以上的热处理对纯Ti的组织和疲劳性能的影响

商业纯Ti（CP-Ti）在1273 K（1000°C）处进行热处理，高于β-转变温度，然后进行水淬。1000℃下的停留时间从1更改为240 h。在1000°C下的热处理导致α晶粒粗化，而马氏体相变是由于β相的快速冷却而发生的。马氏体相变增加了硬度，在1000°C下较长的停留时间可实现更高的硬度。但是，经热处理的CP-Ti的疲劳强度低于所接受的疲劳强度。在不同停留时间的热处理样品中，最短停留时间为1 h的样品的疲劳强度最低。热处理后的样品中观察到未转变的粗α晶粒，