杯形件温挤压成形的计算机模拟和试验研究
发布时间：2019-05-11 14:39
【摘要】：挤压技术在汽车、航空航天、军工、轻工、电器等行业已广泛应用,挤压成形技术是一种少无切屑的成形工艺,具有优质、高效、低消耗的显著特点。近年来,介于冷、热挤压间的温挤压是国内外发展前沿较好的一种毛坯精化新工艺。温挤压适用于冷挤压成形时变形抗力高、塑性差的高强度合金、耐蚀耐热钢、不锈钢和合金钢等材料的成形。在汽车、拖拉机、发动机、军工和航空航天等领域应用广泛。为解决某军工企业杯形件的材料利用率低的问题,本文提出了对杯形件采用温挤压冷整形的综合精密挤压成形技术。主要研究内容和研究成果有:1、对杯形件温挤压成形工艺进行深入的理论分析及研究,发现温挤压成形后的制件尺寸精度和表面粗糙度均达不到预期要求,且具有加工硬化等特征;因此提出了先温成形,后冷整形的复合成形工艺方案,其内形尺寸精度满足了产品技术要求。2、依据成形工艺方案设计合理的模具结构;设计的模具不但满足了强、韧度的要求,而且具有良好的稳定性和可靠性,拆除、更换方便。3、以刚塑性有限元为理论基础,以deform为模拟分析软件,建立了杯形件的温挤压成形数值模拟方案,经数值模拟分析了温挤压成形过程中的金属流动规律、应力、应变及缺陷、各种工艺参数对此零件挤压成形的影响及模具在工作中的挤压受力情况,找出模具结构和工艺参数对成形过程的影响因素,得到了最理想的成形参数:即温度为750℃,挤压速度为5mm/s时,材料塑性良好,变形均匀,流动应力低,无裂纹产生。这一数值模拟分析为此类零件或相似件的实际生产提供了充分的理论依据。4、用实验的方法验证该工艺的可行性,成形出了Qg形不需二次机加工、内腔一次成型的杯形件,其表面的粗糙度值达到Ra=0.8,垂直度与平行度均达到0.01,硬度最大值HRC=38,硬度分布情况为:杯壁中上部的硬度值最大,口部稍微低些,底部的硬度值最小。本文所提供的工艺及模具结构具有一定的工艺先进性和技术创新性,达到了省材和高效生产的目的。为此类零件的温挤压成形提供了新的思路与方法,具有一定的理论意义和实用前景。5、成形后的杯形件,尺寸精度、表面粗糙度、表面硬度等满足设计要求。
[Abstract]:Extrusion technology has been widely used in automobile, aerospace, military, light industry, electrical appliances and other industries. Extrusion forming technology is a kind of forming process without chip, which has the remarkable characteristics of high quality, high efficiency and low consumption. In recent years, warm extrusion between cold and hot extrusion is a new process of blank refinement at home and abroad. Warm extrusion is suitable for cold extrusion forming of high strength alloys with high deformation resistance and poor plasticity, corrosion resistance and heat resistance steel, stainless steel and alloy steel. It is widely used in automobile, tractor, engine, military industry, aerospace and other fields. In order to solve the problem of low material utilization ratio of cup parts in a military enterprise, a comprehensive precision extrusion forming technology for cup parts by warm extrusion and cold shaping is proposed in this paper. The main research contents and research results are as follows: 1. After in-depth theoretical analysis and research on the warm extrusion forming process of cup parts, it is found that the dimensional accuracy and surface roughness of the parts after warm extrusion can not meet the expected requirements. It has the characteristics of working hardening and so on. Therefore, the composite forming process scheme of first temperature forming and cold shaping is put forward, and the dimensional accuracy of the inner shape meets the technical requirements of the product. 2, according to the forming process scheme, the reasonable die structure is designed. The designed die not only meets the requirements of strength and toughness, but also has good stability and reliability, easy to remove and replace. 3, based on rigid-plastic finite element theory and deform as simulation analysis software, The numerical simulation scheme of warm extrusion forming of cup parts is established, and the metal flow law, stress, strain and defects in the process of warm extrusion forming are analyzed by numerical simulation. The influence of various process parameters on the extrusion forming of the part and the extrusion force of the die in the work are found out, and the most ideal forming parameters are obtained: the temperature is 750 鈩，
本文编号：2474575
[Abstract]:Extrusion technology has been widely used in automobile, aerospace, military, light industry, electrical appliances and other industries. Extrusion forming technology is a kind of forming process without chip, which has the remarkable characteristics of high quality, high efficiency and low consumption. In recent years, warm extrusion between cold and hot extrusion is a new process of blank refinement at home and abroad. Warm extrusion is suitable for cold extrusion forming of high strength alloys with high deformation resistance and poor plasticity, corrosion resistance and heat resistance steel, stainless steel and alloy steel. It is widely used in automobile, tractor, engine, military industry, aerospace and other fields. In order to solve the problem of low material utilization ratio of cup parts in a military enterprise, a comprehensive precision extrusion forming technology for cup parts by warm extrusion and cold shaping is proposed in this paper. The main research contents and research results are as follows: 1. After in-depth theoretical analysis and research on the warm extrusion forming process of cup parts, it is found that the dimensional accuracy and surface roughness of the parts after warm extrusion can not meet the expected requirements. It has the characteristics of working hardening and so on. Therefore, the composite forming process scheme of first temperature forming and cold shaping is put forward, and the dimensional accuracy of the inner shape meets the technical requirements of the product. 2, according to the forming process scheme, the reasonable die structure is designed. The designed die not only meets the requirements of strength and toughness, but also has good stability and reliability, easy to remove and replace. 3, based on rigid-plastic finite element theory and deform as simulation analysis software, The numerical simulation scheme of warm extrusion forming of cup parts is established, and the metal flow law, stress, strain and defects in the process of warm extrusion forming are analyzed by numerical simulation. The influence of various process parameters on the extrusion forming of the part and the extrusion force of the die in the work are found out, and the most ideal forming parameters are obtained: the temperature is 750 鈩，
本文编号：2474575
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