【作者】 徐磊；

【导师】 赵国群；

【作者基本信息】 山东大学 ， 材料加工工程， 2013， 硕士

【摘要】 工程机械是我国装备工业的重要组成部分,广泛应用于国防、交通,能源、水利、建筑、道路和城市建设等领域。近十年来,随着中国工程机械应用量的不断增长,履带板市场得到飞速发展。湿地履带板是工程机械在湿地环境下作业的关键部件,使用条件十分恶劣,其硬度、抗拉强度、屈服强度、冲击韧度等力学性能必须满足使用要求。目前我国湿地履带板多采用铸造方法生产,铸造成形容易产生铸造缺陷,进而导致产品组织粗糙、精度降低、力学性能变差。传统的铸造工艺引起的铸造缺陷严重影响了产品的可靠性与质量,导致在产能和产品质量上都无法满足市场需求。因此,研究湿地履带板的成形工艺,制造优质履带板,对我国工程机械行业具有重要意义。本文在综合分析湿地履带板成形技术要求的基础上,提出了一种湿地履带板的锻造成形新工艺,采取锻造工艺代替铸造工艺,从而达到改善产品质量和提高产品可靠性及使用寿命的目的。本文首先对湿地履带板锻造工艺进行了分析,绘制了湿地履带板的计算毛坯图,确定了锻造设备吨位,设计了湿地履带板的初始锻造工艺流程,在“预锻成形、终锻精整”经验基础上,设计了湿地履带板预锻模膛与终锻模膛。然后建立了湿地履带板锻造成形过程的有限元数值模拟模型,采用有限元模拟软件DEFORM-3D对湿地履带板预锻成形过程进行了数值分析,揭示了金属成形过程流动规律,分析了等效应力、应变、温度分布规律及力能曲线。对不同设计方案进行了数值建模和分析,通过对比不同设计方案下的模拟结果,确定了最佳锻造工艺及预制坯形状,并对预锻、终锻过程进行了数值模拟,获得了金属成形过程的流动规律及应力应变场、温度场分布和力能曲线。在此基础上确定了最佳工艺的辊锻模膛、压扁模膛及整体锻模结构。更多还原

【Abstract】 Engineering machinery is an important part of the equipment industry. It’s widely used in the field of national defense, transportation, energy, water conservancy, construction, road and urban construction. In the last10years, the creeper tread market has received tremendous development with the growing application of engineering machinery in China. The wetland creeper tread is the key component of engineering machinery operated in the environment of wetland. Since its service condition is very bad, its hardness, tensile strength, yield strength, impact toughness and other mechanical properties must meet the requirements.At present, our wetland creeper tread is mainly produced by casting method which is prone to causing casting defects and leading to rough products, low accuracy and bad mechanical properties. Casting defects caused by the traditional casting process greatly affect the reliability and quality of the product. Thus the production capacity and product quality could not meet the market requirement. Therefore, it’s of great significance for our engineering machinery industry to study the forming process of wetland creeper tread and produce wetland creeper tread of high-quality.Based on the comprehensive analysis of the wetland creeper tread’s forming process, the paper proposed a new forging forming technology of wetland creeper tread. In place of casting process, the forging process can attain the goal of improving product quality, product reliability and service life.The paper analyzes the forging process, gets the calculation blank drawing, determines the equipment tonnage and gets the initial forging process of wetland creeper tread. Then the die cavity of pre-forging and finish-forging are designed on the basis of "Forming by pre-forging and finishing by finish-forging". The finite element model of wetland creeper tread’s forming process is established and the finite element software DEFORM-3D is used to simulate the pre-forging process. The flowing law of metal and load-stroke curve are predicted. The distribution of the stress and strain, temperature and the equivalent strain rate are obtained. Finite element models of different design schemes are designed and analyzed. The best forging process and the shape of preforming billet are determined by comparing the simulation results of different design schemes. The flowing law of metal, load-stroke curve and distribution of stress, strain, temperature and equivalent strain rate are obtained by simulating the pre-forging and finish-forging process. On this basis, the rolling forging die, pressing die and the whole forging die structure are determined.更多还原