Deformation behaviors of 21-6-9 stainless steel tube numerical control bending under different friction conditions

Abstract

For contact dominated numerical control (NC) bending process of tube, the effect of friction on bending deformation behaviors should be focused on to achieve precision bending forming. A three dimensional (3D) elastic-plastic finite element (FE) model of NC bending process was established under ABAQUS/Explicit platform, and its reliability was validated by the experiment. Then, numerical study on bending deformation behaviors under different frictions between tube and various dies was explored from multiple aspects such as wrinkling, wall thickness change and cross section deformation. The results show that the large friction of wiper die–tube reduces the wrinkling wave ratio η and cross section deformation degree ΔD and increases the wall thinning degree Δt. The large friction of mandrel–tube causes large η, Δt and ΔD, and the onset of wrinkling near clamp die. The large friction of pressure die–tube reduces Δt and ΔD, and the friction on this interface has little effect on η. The large friction of bending die–tube reduces η and ΔD, and the friction on this interface has little effect on Δt. The reasonable friction coefficients on wiper die–tube, mandrel–tube, pressure die–tube and bending die–tube of 21-6-9 (0Cr21Ni6Mn9N) stainless steel tube in NC bending are 0.05–0.15, 0.05–0.15, 0.25–0.35 and 0.25–0.35, respectively. The results can provide a guideline for applying the friction conditions to establish the robust bending environment for stable and precise bending deformation of tube bending.

Keywords

21-6-9 stainless steel tube / friction / deformation behaviors / numerical control bending / finite element simulation

References

[1] YangH, SunZ-c, LinY, LiM-qi. Advanced plastic processing technology and research progress on tube forming [J]. Journal of Plasticity Engineering, 2001, 8(2): 86-88

[2] YanJ, YangH, ZhanM, LiHeng. Forming limits under multi-index constraints in NCbending of aluminum alloy thin-walled tubes with larger diameters [J]. Science China: Technological Sciences, 2010, 53(2): 326-342

[3] TangN C. Plastic-deformation analysis in tube bending [J]. International Journal of Pressure Vessels and Piping, 2000, 77(12): 751-759

[4] WangJ, AgarwalR. Tube bending under axial force and internal pressure [J]. Journal of Manufacturing Science and Engineering, 2006, 128(2): 598-605

[5] PanK, StelsonK A. On the plastic deformation of a tube during bending [J]. Journal of Engineering for Industry, 1995, 117(4): 494-499

[6] WangX, CaoJian. Wrinkling limit in tube bending [J]. Journal of Engineering Materials and Technology, 2001, 123(4): 430-435

[7] LiH, YangH, ZhanMei. A study on plastic wrinkling in thin-walled tube bending via an energy-based wrinkling prediction model [J]. Modelling and Simulation in Materials Science and Engineering, 2009, 17(3): 1-33

[8] YangH, LinYan. Wrinkling analysis for forming limit of tube bending processes [J]. Journal of Materials Processing Technology, 2004, 152(3): 363-369

[9] FangJ, LuS-q, WangK-L, XuJ-m, XuX-m, YaoZ-jun. Effect of mandrel on cross-section quality in numerical control bending process of stainless steel 2169 small diameter tube [J]. Advances in Materials Science and Engineering, 2013, 2013: 1-9

[10] FangJ, LuS-q, WangK-L, XuX-m, XuJ-m, YaoZ-jun. FE analysis of section distortion in numerical control bending of the 0Cr21Ni6Mn9N stainless steel tube [J]. Journal of Plasticity Engineering, 2013, 20(5): 71-76

[11] ZhanM, HuangT, JiangZ-q, ZhangP-p, YangHe. Determination of process parameters for the NCbending of a TA18 tube [J]. The International Journal of Advanced Manufacturing Technology, 2013, 68: 663-672

[12] ZhanM, JiangZ-q, YangH, XuX-d, LiG-jun. Numerically controlled bending preformance of medium strength TA18 titanium alloy tubes under different die sets [J]. Science China: Technological Sciences, 2011, 54(4): 841-852

[13] LiH, YangH, ZhanM, KouY-le. Deformation behaviors of thin-walled tube in rotary draw bending under push assistant loading conditions [J]. Journal of Materials Processing Technology, 2010, 210(1): 143-158

[14] LiH, YangHe. A study on Multi-defect constrained bendability of thin-walled tube NCbending under different clearance [J]. Chinese Journal of Aeronautics, 2011, 24(1): 102-112

[15] LiH, YangH, ZhangZ-y, WangZ-kang. ‘Size effect’ related bending formability of thin-walled aluminum alloy tube [J]. Chinese Journal of Aeronautics, 2013, 26(1): 230-241

[16] LiH, YangH, YanJ, ZhanMei. Numerical study on deformation behaviors of thin-walled tube NCbending with large diameter and small bending radius [J]. Computational Materials Science, 2009, 45(4): 921-934

[17] LiH, YangH, ZhanM, GuR-jie. Forming characteristics of thin-walled tube bending process with small bending radius [J]. Transactions of Nonferrous Metals Society of China, 2006, 16(2): s613-s623

[18] JiangZ-q, ZhanM, YangH, XuX-d, LiG-jun. Deformation behavior of medium-strength TA18 high-pressure tubes during NCbending with different bending radii [J]. Chinese Journal of Aeronautics, 2011, 24(5): 657-664

[19] YangH, GuR-j, ZhanM, LiHeng. Effect of frictions on cross section quality of thin-walled tube NCbending [J]. Transactions of Nonferrous Metals Society of China, 2006, 16(4): 878-886

[20] YangH, LiH, ZhanMei. Friction role in bending behaviors of thin-walled tube in rotary-draw-bending under small bending radii [J]. Journal of Materials Processing Technology, 2010, 210(15): 2273-2284

[21] YangH, YanJ, ZhanM, LiH, KouY-le. 3D numerical study on wrinkling characteristics in NCbending of aluminum alloy thin-walled tubes with large diameters under multi-die constraints [J]. Computational Materials Science, 2009, 45(4): 1052-1067

[22] LiC, YangH, ZhanM, XuX-d, LiG-jun. Effects of process parameters on numerical control bending process for large diameter thin-walled aluminum alloy tubes [J]. Transactions of Nonferrous Metals Society of China, 2009, 19(3): 668-673

[23] WangG-x, YangH, LiH, ZhanM, GuR-jie. Experimental study of the influence of process parameters on forming quality of thin-walled^NCbending tube [J]. Mechanical Science and Technology, 2005, 24(8): 995-998

[24] KouY-l, YangH, ZhanM, YueY-b, LiHeng. Experimental study on cross-section ovalization of thin-walled tube in NCbending process [J]. Journal of Plasticity Engineering, 2007, 14(5): 26-31

[25] YueY-baoNumerical simulation and experiment study on Ti-Alloy tube NCbending process [D], 2009Xi’anNorthwestern Polytechnical University

[26] GB/T228.1—2010. Metallic materials–Tensile testing at ambient temperature [S]. (in Chinese)

[27] LiHengStudy on wrinkling behaviors under multi-die constraints in thin-walled tube NCbending [D], 2007Xi’anNorthwestern Polytechnical University