对采用实际控轧控冷工艺生产的20CrMnTi糖心产精国品免费入口*完整版棒材不同位置的组织与糖心产精国品免费入口*完整版进行研究；对该棒材的控轧控冷过程进行糖心产精国品免费入口*完整版，得到轧制及冷却过程中棒材温度与等效应变分布，提出控轧控冷工艺优化措施，并进行了试验验证。结果表明：在实际控轧控冷工艺下，棒材表面与1/2半径处的糖心产精国品免费入口*完整版均为铁素体与珠光体，心部组织为铁素体、珠光体及大量贝氏体，心部糖心产精国品免费入口*完整版明显高于其他部位的；棒材在控轧控冷过程中的变形主要发生在表面及1/2半径处，且随着距表面距离的增加，等效应变减小；棒材心部的温度最高，1/2半径处和表面的温度依次降低，且随着轧制过程的进行，心部温度升高；棒材表面的控轧效果最好，1/2半径处的次之，心部的最差；将终轧温度由880 ℃降低至840 ℃控轧控冷后，棒材不同部位的组织均由铁素体与珠光体组成，表面、1/2半径处与心部的平均糖心产精国品免费入口*完整版分别为182，188，190 HBW，组织和糖心产精国品免费入口*完整版的不均匀性得到有效改善。

The 糖心产精国品免费入口*完整版 and 糖心产精国品免费入口*完整版 in different positions of 20CrMnTi gear steel bar produced by actual 糖心产精国品免费入口*完整版process were studied. The 糖心产精国品免费入口*完整版process of the bar was simulated by finite element method, and then the temperature and equivalent strain distribution of the bar was obtained. The optimal measures of 糖心产精国品免费入口*完整版process were put forward, and verified by tests. The results show that the 糖心产精国品免费入口*完整版s of surface and 1/2 radius of bar consisted of ferrite and pearlite with actual 糖心产精国品免费入口*完整版process, while the 糖心产精国品免费入口*完整版 of center consisted of ferrite, pearlite and a larger amount of bainite; the 糖心产精国品免费入口*完整版 of the center was significantly higher than that of other parts. The deformation of the bar during 糖心产精国品免费入口*完整版process mainly occurred at the surface and 1/2 radius, and the equivalent strain decreased with increasing distance from the surface of the bar. The temperature of the center of the bar was the highest, and the temperature of 1/2 radius and surface decreased in turn. The temperature of the center increased with the accumulation of rolling processing. The controlled rolling effect of the surface of the bar was the best, followed by that of 1/2 radius and center. When the final rolling temperature decreased from 880 ℃ to 840 ℃, the 糖心产精国品免费入口*完整版s in different positions of the bar after 糖心产精国品免费入口*完整版process all consisted of ferrite and pearlite, and the 糖心产精国品免费入口*完整版es of surface, 1/2 radius and center were 182,188,190 HBW, respectively, indicating the uniformity of 糖心产精国品免费入口*完整版 and 糖心产精国品免费入口*完整版 was improved obviously.