微观组织遗传性是实现TA18合金微观组织和性能调控的基础。本工作以TA18合金铸锭、不同规格锻棒、挤压管坯为研究对象，研究了从铸锭到管坯全流程中微观组织和织构演变的遗传规律，及其对力学性能的影响，旨在为多尺度微观组织和性能的一体化控制提供指导。结果表明，从铸锭到管坯全流程，其组织遗传特征主要分为三类。(1) 微米级晶粒尺寸和等轴α相组织形貌在粗锻阶段建立后，在后续工序中被稳定遗传，晶粒细化是轴向抗拉强度从400 MPa提升至550 MPa以及延伸率提高的基础。(2) 小角度晶界(LAGB)含量的遗传则呈现动态演化。粗锻与精锻阶段的高LAGB含量遗传贡献了加工硬化，但损害塑性；挤压阶段通过完全再结晶实现LAGB低含量遗传，塑性得以恢复。(3) 晶体学织构的遗传受多重因素控制。铸锭中心区域的{0001}∥AD (轴向)基面织构与1010∥AD织构在后续加工过程中被强烈遗传，且1010∥AD织构强度持续增加；α相的c轴取向随工艺发生受控演变：粗锻后呈随机分布，精锻后转为径向织构，挤压后则形成周向织构。TA18合金通过原始组织的晶体取向、变形、动态再结晶机制的竞争与协同，耦合控制晶体学取向的遗传与演化，可通过对有益遗传(细晶、有利织构)的强化与有害遗传(高含量LAGB、不利织构)的阻断进行一体化设计，获得兼具高强度与良好塑性的TA18合金管坯。

In metallic material processing, the microstructural and textural characteristics developed during each manufacturing stage establish the structural foundation for subsequent processing operations, creating substantial hereditary effects throughout the multistage manufacturing chain. This progressive, cross-process accumulation of microstructural and textural evolution makes precise tracing and effective control of microstructural inheritance pathways particularly complex during full-scale manufacturing from the initial ingot to the final TA18 tube blank. Microstructural inheritance forms the basis for structural design and property optimization in TA18 alloys. This investigation employed a 700-mm diameter TA18 alloy ingot as the starting material. The thermomechanical processing route comprised three stages: initial multipass forging in the β-phase field (1150℃–950℃) followed by forging in the α+β phase field at 900℃ to produce a 170-mm diameter rough-forged bar; subsequent processing of the rough-forged bar in the two-phase region at 850°C to obtain a 125-mm diameter finish-forged bar; finally, peeling, drilling, and canned hot extrusion of the finish-forged bar to fabricate tube blanks with inner and outer diameters of 28 and 42 mm, respectively. This study systematically investigates the hereditary evolution of microstructure and texture throughout the processing route from ingot to tube blank in the TA18 alloy and evaluates its impact on mechanical properties to guide the integrated control of multiscale microstructure and performance. The results demonstrate that microstructural hereditary characteristics can be categorized into three primary types. (1) Once established during rough forging, the micron-scale grain size and equiaxed α-phase morphology remain stably inherited in subsequent processing stages. Grain refinement serves as the fundamental basis for increasing axial tensile strength from 400 to 550 MPa and improving elongation. (2) The inheritance of low-angle grain boundary (LAGB) content exhibits dynamic evolution. The high content inherited during the rough- and finish-forging stages contributes to work hardening but negatively affects plasticity; in contrast, the low content inherited after extrusion, achieved via complete recrystallization, results in plasticity recovery. (3) The inheritance of crystallographic texture is governed by multiple competing mechanisms. The {0001}∥axial direction (AD) basal texture and the1010∥AD texture originating from the central region of the ingot are strongly inherited during subsequent processing, with the intensity of the1010∥AD texture continuously increasing. The c-axis orientation of the α-phase undergoes controlled evolution during processing: it is randomly distributed after rough forging, transforms into a radial texture after finish forging, and finally develops into a circumferential texture after extrusion. The TA18 alloy controls the inheritance and evolution of crystallographic orientation through the competition and synergy of various mechanisms, including initial crystallographic orientation, deformation, and dynamic recrystallization. The integrated design of TA18 alloy tube blanks, possessing high strength and good plasticity can be achieved by reinforcing beneficial hereditary features (such as fine grains and favorable texture) and interrupting harmful features (such as high LAGB content and unfavorable texture).