Multi-direction loading forming technology provides an effective way for green manufacturing of high-performance multi-cavity complex parts of 316LN steel, which are widely used in nuclear power pipelines. In this forming process, the material needs to undergo complex unequal deformation under a mixed stress state of tensile-shear, compression-shear and shear, flow and fill the cavity to obtain such complicated shape only from the simple cylindrical blank, thus forming defects are prone to occurring and restrict the forming feasibility, which is related to both process parameters and the geometric structures to be formed. In this paper, by considering the uniformity of deformation and temperature distribution, along with the forming load, the reasonable forming parameters were analyzed and obtained. The results showed that the deformation uniformity could be improved as the punch loading speed increased or the friction factor decreased. A lower forming load could be realized by reducing the loading speed of punches or raising the initial blank temperature. Then under the recommended process parameters, the reasonable range of geometric dimension of parts to be formed was acquired by investigating the velocity field, forming load, folding length, and damage distribution. When ratio of the branch pipe spacing to outer diameter of main pipe is L_m/D₀ ≤ 0.5 or inner-outer diameter ratio of main pipe d₀/D₀ ≥ 0.8, the cracking would occur. When length of main pipe L₀ = D₀ or inner-outer diameter ratio of branch pipe is d₁/D₁ ≤ 0.6, both folding and cracking presented. Consequently, the acquired forming feasibility can provide guidance for the application of multi-direction loading forming process for multi-cavity complex parts.

多方向载荷成形技术为绿色制造高性能316LN钢的多腔复杂零件提供了有效的方法，该零件广泛应用于核电管道。在这种成型过程中，材料需要在拉伸剪切，压缩剪切和剪切的混合应力状态下经历复杂的不均匀变形，仅从简单的圆柱形毛坯中流动并填充模腔才能获得如此复杂的形状，从而形成缺陷容易发生并限制了成形的可行性，这与工艺参数和要成形的几何结构有关。本文通过考虑变形和温度分布的均匀性，以及成形载荷，对合理的成形参数进行了分析和获取。结果表明，随着冲头加载速度的增加或摩擦系数的减小，变形均匀性得到改善。通过降低冲头的加载速度或提高初始毛坯温度，可以实现较低的成型负载。然后在推荐的工艺参数下，通过研究速度场，成形载荷，折叠长度和损伤分布，来确定要成形零件的几何尺寸的合理范围。当支管间距与主管外径之比为 通过研究速度场，成形载荷，折叠长度和损伤分布，可以确定要成形零件的几何尺寸的合理范围。当支管间距与主管外径之比为 通过研究速度场，成形载荷，折叠长度和损伤分布，可以确定要成形零件的几何尺寸的合理范围。当支管间距与主管外径之比为大号_米/ d ₀  ≤0.5或主配管的内外径比d ₀ / d ₀  ≥0.8，会发生开裂。当主配管的长度大号₀  =  d ₀或内外支管的直径比d ₁ / d ₁  ≤0.6，两个折叠和裂纹呈现。因此，所获得的成形可行性可以为多腔复杂零件的多方向载荷成形工艺的应用提供指导。