(哈爾濱工業(yè)大學 材料科學與工程學院，哈爾濱 150001)
摘 要: 介紹哈爾濱工業(yè)大學在內(nèi)高壓成形基礎理論、關鍵技術及工業(yè)應用等方面取得的重要進展。在基礎理論方面，利用平面應力屈服橢圓描述典型內(nèi)高壓成形過程中應力狀態(tài)及壁厚變化趨勢；揭示變徑管內(nèi)高壓成形過程中壁厚分布規(guī)律以及多邊形截面環(huán)向的壁厚分布特點；指明整形階段圓角充填時存在極限圓角半徑；發(fā)明了用于測量管材環(huán)向力學性能的管材環(huán)向拉伸實驗方法。在工藝關鍵技術方面，針對航空航天領域對大直徑薄壁復雜管件的需求，發(fā)明了Y型薄壁三通管兩步成形方法、雙層管充液彎曲方法，試制出超薄Y型三通管、整體不銹鋼進氣道及彎管零件。在工業(yè)應用方面，研制了合模力最大達55 MN的工業(yè)生產(chǎn)用大型內(nèi)高壓成形機，并成功地用于轎車底盤零件大批量生產(chǎn)。
關鍵字: 內(nèi)高壓成形；液壓成形；塑性變形；應力狀態(tài)；失穩(wěn)行為
internal high pressure forming
（School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China）
Abstract:Important progresses and achievements in fundamental theory, key processes and industrial applications of tube hydroforming realized in engineering research center of hydroforming/harbin institute of technology (ERCH/HIT) were introduced. Typical stress states in tube hydroforming process and the corresponding thickness changing tendency were given on the plane stress yield loci. Thickness changes along the axial direction of tubular part with changeable diameters and the hoop direction of tubular part with rectangular cross-section were given. The concept of limited corner radius in calibration process was proposed and analyzed. Ring hoop tension test was proposed to evaluate the mechanical properties of tube along hoop direction. Multi-step method for the forming of thin Y-shaped branch tube, and double-layered hydro-bending method for the forming of thin-walled bent tubular part were proposed. Ultra-thin Y-shaped branch tube, integral stainless steel tube, and bent tubular part for aerospace application were manufactured. Hydroforming machine of 55 MN maximal closing force was developed. Typical parts for automotive industry, such as engine cradle, front beam holder and torsion beam, were manufactured.
Key words: internal high pressure forming (IHPF); hydroforming; plastic forming; stress state; instability behavior
