Marginal-restraint mandrel-free spinning is an advanced technology for manufacturing ellipsoidal heads with large diameter-thickness ratios. The effects of spinning parameters on the forming accuracy of ellipsoidal heads have been studied, and optimized spinning parameters have been obtained. The microstructure evolution of a workpiece is usually very complicated in the spinning process. In this work, the influence of spinning parameters on the microstructures of two-pass spun ellipsoidal heads is studied. It is found that the forming angle and feed rate of the first pass, angle between passes, and feed rate of the second pass significantly affect the microstructures. Meanwhile, the evolution rule of the microstructures near the inner and outer surfaces of the spun parts is almost consistent. A large forming angle, large angle between passes, or large feed rate of the second pass are beneficial to obtain uniform microstructures. A small or large feed rate of the first pass reduces the microstructure uniformity. To improve the microstructure uniformity between the inner and outer surfaces, the optimized spinning parameters are determined.

边际约束无心轴纺丝技术是一种先进的技术，用于制造直径/厚度比大的椭圆头。研究了旋转参数对椭圆头成形精度的影响，并获得了优化的旋转参数。在旋转过程中，工件的微观结构演变通常非常复杂。在这项工作中，研究了旋转参数对两遍旋转椭圆头的微观结构的影响。发现第一道次的成形角度和进给速率，道次之间的角度以及第二道次的进给速率显着影响了显微组织。同时，在旋转部件的内表面和外表面附近的微观结构的演化规则几乎是一致的。较大的成型角度，道次之间的角度 或第二道次的大进料速率有利于获得均匀的微观结构。第一道次的进料速率大或小都会降低微观结构的均匀性。为了改善内表面和外表面之间的微观结构均匀性，确定了优化的纺丝参数。