航天用超大规格GH4169高温合金螺栓热镦工艺

Hot upsetting process of super-sized superalloy GH4169 bolts for aerospace

为研究一种航天用超大规格GH4169高温合金螺栓热镦工艺,利用热模拟试验机对材料进行了高温压缩实验,分析了不同变形温度和应变速率对材料变形抗力的影响,并对GH4169高温合金螺栓的热镦成形过程进行了数值模拟,分析了成形过程中等效应力场分布、损伤值分布、金属流线分布、摩擦因数对成形载荷的影响,最后进行了工艺实验。研究结果表明:应变速率一定时,随着变形温度的升高,材料的变形抗力逐渐降低;变形温度一定时,随应变速率的增大,材料的变形抗力逐渐增大;摩擦因数μ=0.3时成形过程中的最大载荷为3.56×10^(6)N,摩擦因数μ=0.5时成形过程中的最大载荷为4.11×10^(6)N。工艺实验得到的GH4169高温合金螺栓锻件充填饱满,尺寸符合要求,未发现锻造缺陷,符合航天领域使用需求。

In order to study the hot upsetting process of super-sized GH4169 superalloy bolts for aerospace, the high-temperature compression experiment of material was carried out by the thermal simulation testing machine, and the influences of different deformation temperatures and strain rates on the deformation resistance of material were analyzed. Then, the hot upsetting process of superalloy GH4169 bolts was numerically simulated, and the influences of the distributions of equivalent stress field, damage value and metal streamline, and friction factor on forming load during the forming process were analyzed. Finally, the process experiment was carried out. The results show that when the strain rate is constant, the deformation resistance of material decreases gradually with the increaseing of deformation temperature. When the deformation temperature is constant, the deformation resistance of material increases gradually with the increaseing of strain rate. When the friction factor μ=0.3, the maximum load in the forming process is 3.56×10^(6) N,and when the friction factor μ=0.5, the maximum load in the forming process is 4.11×10^(6) N. The superalloy GH4169 bolt forgings obtained by the process experiment are fully filled, the sizes meet the requirements, and no forging defects are found, which meets the using needs of aerospace field.