【摘要】：擠壓技術(shù)在汽車(chē)、航空航天、軍工、輕工、電器等行業(yè)已廣泛應(yīng)用,擠壓成形技術(shù)是一種少無(wú)切屑的成形工藝,具有優(yōu)質(zhì)、高效、低消耗的顯著特點(diǎn)。近年來(lái),介于冷、熱擠壓間的溫?cái)D壓是國(guó)內(nèi)外發(fā)展前沿較好的一種毛坯精化新工藝。溫?cái)D壓適用于冷擠壓成形時(shí)變形抗力高、塑性差的高強(qiáng)度合金、耐蝕耐熱鋼、不銹鋼和合金鋼等材料的成形。在汽車(chē)、拖拉機(jī)、發(fā)動(dòng)機(jī)、軍工和航空航天等領(lǐng)域應(yīng)用廣泛。為解決某軍工企業(yè)杯形件的材料利用率低的問(wèn)題,本文提出了對(duì)杯形件采用溫?cái)D壓冷整形的綜合精密擠壓成形技術(shù)。主要研究?jī)?nèi)容和研究成果有:1、對(duì)杯形件溫?cái)D壓成形工藝進(jìn)行深入的理論分析及研究,發(fā)現(xiàn)溫?cái)D壓成形后的制件尺寸精度和表面粗糙度均達(dá)不到預(yù)期要求,且具有加工硬化等特征;因此提出了先溫成形,后冷整形的復(fù)合成形工藝方案,其內(nèi)形尺寸精度滿足了產(chǎn)品技術(shù)要求。2、依據(jù)成形工藝方案設(shè)計(jì)合理的模具結(jié)構(gòu);設(shè)計(jì)的模具不但滿足了強(qiáng)、韌度的要求,而且具有良好的穩(wěn)定性和可靠性,拆除、更換方便。3、以剛塑性有限元為理論基礎(chǔ),以deform為模擬分析軟件,建立了杯形件的溫?cái)D壓成形數(shù)值模擬方案,經(jīng)數(shù)值模擬分析了溫?cái)D壓成形過(guò)程中的金屬流動(dòng)規(guī)律、應(yīng)力、應(yīng)變及缺陷、各種工藝參數(shù)對(duì)此零件擠壓成形的影響及模具在工作中的擠壓受力情況,找出模具結(jié)構(gòu)和工藝參數(shù)對(duì)成形過(guò)程的影響因素,得到了最理想的成形參數(shù):即溫度為750℃,擠壓速度為5mm/s時(shí),材料塑性良好,變形均勻,流動(dòng)應(yīng)力低,無(wú)裂紋產(chǎn)生。這一數(shù)值模擬分析為此類(lèi)零件或相似件的實(shí)際生產(chǎn)提供了充分的理論依據(jù)。4、用實(shí)驗(yàn)的方法驗(yàn)證該工藝的可行性,成形出了Qg形不需二次機(jī)加工、內(nèi)腔一次成型的杯形件,其表面的粗糙度值達(dá)到Ra=0.8,垂直度與平行度均達(dá)到0.01,硬度最大值HRC=38,硬度分布情況為: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。本文所提供的工藝及模具結(jié)構(gòu)具有一定的工藝先進(jìn)性和技術(shù)創(chuàng)新性,達(dá)到了省材和高效生產(chǎn)的目的。為此類(lèi)零件的溫?cái)D壓成形提供了新的思路與方法,具有一定的理論意義和實(shí)用前景。5、成形后的杯形件,尺寸精度、表面粗糙度、表面硬度等滿足設(shè)計(jì)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，

本文編號(hào)：2474575