【作者】 孙超；

【导师】 赵长财；

【作者基本信息】 燕山大学 ， 材料加工工程， 2011， 硕士

【摘要】 本课题来源于GM课题组与无锡透平叶片有限公司的横向课题《叶片锻件镦头工艺技术及通用模架技术》。叶片广泛应用于大型电站汽轮机、燃汽轮机、航空发动机及各类动力装备,其产品被广泛应用于能源电力、航空航天、船舰装备及石化等领域。目前,国内外普遍采用平锻机锻造来实现镦头工艺。然而采用自由锻制坯方式存在很多问题,诸如坯料尺寸精度低、生产效率低、产品质量取决于工人的操作水平,且成本高、投资大,对于双头镦粗零件需分两次成形等。针对上述问题,基于对无锡透平叶片有限公司所需锻造的航空发动机叶片、汽轮机叶片毛坯锻造工艺进行深入研究,系统分析其成形特点后,本文提出将镦粗、挤压、闭式模锻三个成形工步一次完成的轴类件局部成形新工艺。该工艺采用全新理念,设计了独特的浮动式模具结构,有效解决了细长棒料(长径比>2.5)局部聚料成形工艺中的一系列难题,克服了传统细长杆件局部成形过程塑性失稳、金属折迭、表面开裂等成形缺陷。此外,本文采用有限元数值模拟技术,针对该类零件的锻造成形过程和通用模架结构进行数值模拟,得出锻造成形规律,并设计出一套通过更换模芯即可实现对不同规格不同类型零件镦头的通用模架,使得双头以及长径比在6以内的零件都能通过此模架一次镦粗成形。具有工艺简单、适应面广、材料利用率高、模具寿命高、生产率高、生产成本低等优点,为细长杆形坯料局部精密成形提供了一条有效途径。更多还原

【Abstract】 This subject comes from a horizontal research project of“Heading process and universal mold frame technology for blade forgings”between GM Team and Wuxi Turbine Blade Co., Ltd.Blades are widely used in large power turbines, gas turbines, aircraft engines and all kinds of power equipment. The products are widely used in electric power, aerospace, ship equipment, petrochemical and other fields.At present, the flat forging machine is widely used at home and abroad to achieve the upset head forging process. However, free forging has many problems, such as lower stock size precision, lower productivity, product quality depends on the operational level of workers, and higher cost, larger investment, needs two forming processes for the two-headed upsetting, etc.Taking into account these issues, basing on the deep research on forging of blank of the blade of aero engine and steam turbine, after analyzing the characteristics of the forming, a new technology which makes upsetting, extruding and closed die forging into one process is proposed for the local forming of the axis components in this paper. This technology has adopted the new design concept, a series of problems in the local forming of slender bar (the ratio of length to diameter larger than 2.5) were effectively solved by a mold structure of floating type. It also overcomes the defects that plastic instability, metal folding, surface cracking and so on. This paper adopts finite element numerical analog analysis technique to research the forging forming law of this kind of component and the general mould structure. A new general mould was designed for the upset head of components with different specification and different types. The blank which needs to forging at both ends and the ratio of length to diameter of it is lower than 6 can form at a time through the general mould. In general, this technology has many advantages of simpler technology, wider forming range, higher material utilization, longer service life of die, higher productivity and lower cost, especially in the partial precise deforming process of the slender blank.更多还原