低碳含Cu中厚钢板富Cu相的时效析出行为

将某低碳含Cu中厚钢板在680℃分别时效不同时间(15、30、45、75、90、120 min)后，利用场发射扫描电镜(SEM)和能谱仪(EDS)分析了中厚钢板不同位置富Cu相的析出和长大机制。结果表明，经时效处理后，试验钢板表面及心部富Cu相呈球状或短棒状，尺寸均主要在5～60 nm之间，但心部富Cu相的平均尺寸要大于表面富Cu相。随着时效时间的延长，表面和心部的富Cu相均发生长大，呈现平均尺寸增加、粒子总数目减少的趋势。基于理论计算，富Cu相平均尺寸的变化满足Ostwald熟化机制，且心部富Cu相长大速率小于表面富Cu相。

Aging precipitation behavior of Cu-rich particles of low-carbon Cu-bearing medium and heavy steel plate

A low-carbon Cu-bearing medium and heavy steel plate was aged at 680 ℃ for different time (15, 30, 45, 75, 90, 120 min). The precipitation and growth mechanism of Cu-rich particles at different positions of medium and heavy steel plate were analyzed by field emission scanning electron microscopy (SEM) and energy disperse spectroscopy (EDS). The results show that after aging treatment, the Cu-rich particles on surface and in core of the tested steel plate are spherical or short rod-shaped, and the size is mainly in the range of 5-60 nm, but the average size of Cu-rich particles in the core is larger than that on the surface. With the increase of aging time, the Cu-rich particles on the surface and in the core grow at the same time, showing a trend of the average size increasing and the total number of particles decreasing. Based on the theoretical calculation, the change of average size of Cu-rich particles satisfies the Ostwald ripening mechanism, and the growth rate of Cu-rich particles in the core is smaller than that on the surface.