无缝钢管热轧后控冷工艺的组织性能数值模拟

 为了实现无缝钢管生产工艺流程中定(减)径之后矫直之前的控制冷却，采用数值模拟方法研究了20号钢管轧后冷却过程的组织力学性能变化规律。首先采用试验方法测定钢探头在不同冷却介质条件下的温度变化曲线，根据反传热法基本原理计算得出钢探头冷却过程中表面换热系数与工件温度的关系。然后，采用有限差分法建立了钢管冷却过程中的温度场、组织相变及力能性能预测系统，分析了不同冷却工艺条件下钢管的组织状态与力学性能。最后，进行钢管空冷过程的试验分析，测定了不同时刻的温度数据和冷态钢管的力学性能，其计算结果与实测数据吻合良好。该研究结果可为实现无缝钢管控制冷却提供基础性数据。

Numerical Simulation on Microstructure and Properties of Hot Rolled Seamless Tube in Cooling Process

To realize controlled cooling of seamless tube between sizing and straightening in the production process of automatic plug mill, the laws of microstructural and mechanical properties change of rolled No.20 tube during the cooling process were investigated using numerical simulation method under the different cooling conditions. Firstly, after the cooling curves of steel probe in the different cooling mediums were measured, the relationship of heat transfer coefficient of probe and work piece’s temperature was obtained by programming and solution using the basic principle of inverse heat conduction method. And a predict system of temperature, phase transformation and mechanical properties in the cooling process of tube was established using finite difference method. The cooled phase and properties of tube were analyzed in the different cooling processes. Finally, the air cooling experiment of tubes was carried out and the temperatures at different time of cooling and mechanical properties of tubes were measured. The simulated results are in good agreement with the measured data. These works lay a foundation of controlled cooling of seamless tube.