由于TC4钛合金通常作为航空航天、海洋船舶等领域核心零部件的重要结构材料，为保证零部件综合力学性能，通常采用非等温锻造成形的加工方法制出成品或半成品。然而，TC4钛合金锻造加工难度大，非等温锻造时极易产生较大残余应力。在制造过程中，过大的残余应力会引起锻件变形甚至开裂，降低锻件合格率；在服役过程中，锻件遗留下来的部分残余应力和其它因素引起的残余应力相互叠加，也会严重影响零件的力学性能与尺寸稳定性。因此，深入研究TC4钛合金锻件残余应力对于提高锻件的质量和合格率以及保证装备安全性和可靠性显得至关重要。

本文结合物理实验与仿真模拟对非等温锻造下TC4钛合金锻件残余应力进行分析，主要研究内容如下：

（1）甄别影响非等温锻造下TC4钛合金锻件残余应力的关键锻造工艺参数，制定合适的物理实验方案，得到了锻件残余应力；建立非等温锻造下TC4钛合金锻件残余应力有限元分析模型，实现了与物理实验相对应的仿真模拟，并对比实验结果与仿真结果的误差，修正了残余应力有限元分析模型，保证仿真精度；

（2）采用修正后的非等温锻造下TC4钛合金锻件残余应力有限元分析模型进行仿真模拟，得到了卸载后锻件应力的释放规律、锻件残余应力的分布规律以及各锻造工艺参数对锻件残余应力的影响规律；

（3）以锻造工艺参数为实验因素，以锻件平均等效残余应力作为评价指标建立正交试验，对锻造工艺参数进行了优化，得到了锻造工艺参数对残余应力的影响程度，以及全局内残余应力最小的锻造工艺参数组；综合分析锻造工艺参数对锻件力学性能与残余应力的影响，在尽可能保证锻件力学性能的前提下，得到了能够较大程度上改善锻件残余应力的最优工艺参数组；

（4）以仿真数据为样本，分析数据特征，进行多元线性回归分析，得到了能够较为准确的预测平均等效残余应力的数学模型，为生产实际提供一定的指导。

本文研究结果能够改善锻件残余应力，对提高锻件质量和合格率以及保证装备安全性有积极作用。

TC4 titanium alloy is usually used as an important structural material for core components in the aerospace, marine and other fields. In order to ensure the comprehensive mechanical properties of the parts, Non-isothermal forging is mainly used to produce finished products or semi-finished products. However, the forging process of TC4 titanium alloy is difficult, and it is easy to produce large residual stress under non isothermal forging. In the manufacturing process, excessive residual stress will cause deformation and even cracking of forgings, which will reduce the qualification rate of the forgings. In the service process, the residual stresses left over from the forgings and the residual stresses caused by other factors are superimposed on each other, which will also seriously affect the mechanical properties and dimensional stability of the parts. Therefore, it is very important to study the residual stress of TC4 titanium alloy forgings in depth for improving the quality and qualification rate of forgings and ensuring the safety and reliability of equipment.

In this paper, the residual stress of TC4 titanium alloy forgings under non-isothermal forging is analyzed by physical experiment and numerical simulation. The main research contents are as follows:

(1) The key forging process parameters affecting the residual stress of TC4 titanium alloy forgings under non isothermal forging were identified. An appropriate physical experiment scheme was developed to obtain the residual stress of the forgings. The finite element analysis model of TC4 titanium alloy forging residual stress under non isothermal forging was established, and the simulation corresponding to physical experiment was realized. By comparing the error between the experimental results and the simulation results, the finite element analysis model of residual stress is corrected to ensure the simulation accuracy.

(2) The modified finite element analysis model of TC4 titanium alloy forging residual stress under non isothermal forging is used for simulation. The release rule of forging stress after unloading, the distribution rule of forging residual stress and the influence rule of forging process parameters on forging residual stress are obtained.

(3) Taking the forging process parameters as the experimental factor, the average equivalent residual stress of forging as the evaluation index to establish an orthogonal test, the forging process parameters were optimized, the influence degree of forging process parameters on the residual stress was obtained, and the forging process parameters set with the minimum residual stress in the whole world was obtained. Considering the influence of forging process parameters on the mechanical properties and residual stress of forgings, the optimal process parameters group which can improve the residual stress of forgings to a great extent is obtained under the premise of ensuring the mechanical properties of forgings as much as possible.

(4) Taking the simulation data as samples, analyzing the characteristics of the data, and doing multiple linear regression analysis, a more accurate mathematical model for predicting the average equivalent residual stress is obtained, which provides some guidance for the production practice.

The research results in this paper can improve the residual stress of forgings and play a positive role in improving the quality and qualification rate of forgings and ensuring the safety of equipment.