(1. 山東理工大學(xué) 機(jī)械工程學(xué)院，淄博 255049；
2. 山東理工大學(xué) 計(jì)算機(jī)科學(xué)與技術(shù)學(xué)院，淄博 255049)
摘 要: 提出一種方管自彎曲擠壓新工藝，通過(guò)設(shè)計(jì)傾斜分流橋結(jié)構(gòu)，使金屬在型腔內(nèi)產(chǎn)生不均勻流動(dòng)，從而直接擠出彎曲方管型材。利用外部網(wǎng)格重構(gòu)方法，實(shí)現(xiàn)金屬在型腔內(nèi)分流焊合過(guò)程的模擬分析，得到自彎曲擠壓過(guò)程金屬流動(dòng)規(guī)律、等效應(yīng)力應(yīng)變場(chǎng)分布；研究分流橋傾斜角和擠壓速度對(duì)方管型材自彎曲成形性的影響，并通過(guò)擠壓實(shí)驗(yàn)制備出自彎曲方管。結(jié)果表明：自彎曲模具結(jié)構(gòu)可擠出形狀規(guī)則、曲率一致的彎曲方管件，型材應(yīng)力應(yīng)變分布均勻，隨分流橋傾斜角或擠壓速度的增加，型材曲率半徑呈非線性遞減，擠壓后彎曲方管的上表面、側(cè)面和下表面的晶粒均勻且為等軸晶，晶粒尺寸分別為64.3、61.7和58.3 μm。
關(guān)鍵字: 分流焊合模擬；自彎曲擠壓成形；傾斜分流橋；型材微觀組織
（1. School of Mechanical Engineering, Shandong University of Technology, Zibo 255049, China;
2. School of Computer Science and Technology, Shandong University of Technology, Zibo 255049, China）
Abstract:This paper concerned a novel method for curved square tube profiles self-bending extrusion forming. By designing the inclined shunt bridge structure, the metal can generate internal differential flow, thereby directly extruding the curved square tube profile. Using external mesh reconstruction methods, the numerical simulation of shunt welding extrusion process was realized. The metal flow behavior, stress and strain field distribution in the self-bending extrusion process were obtained. The effects of inclination angle and extrusion ram velocity on the self-bending forming of square tube profiles were studied. The bent square tube profiles were obtained from the extrusion experiment. The results show that the regular and stable bending square tube can be extruded by the self-bending die structure. The distribution of stress and strain is uniform. With the increase of the inclination angle or extrusion ram velocity, the curvature radius of the profile is nonlinearly decreasing. After extrusion, the grains on the upper surface, side surface and lower surface of the curved square tube are uniform and equiaxed, and the grain sizes are 64.3, 61.7 and 58.3 μm, respectively.
Key words: shunt welding simulation; self-bending extrusion; inclined shunt bridge; profile microstructure
