Springback law of high-strength 21-6-9 stainless steel tube in numerical control bending under different process parameters

Abstract

In order to achieve the precision bending deformation, the effects of process parameters on springback behaviors should be clarified preliminarily. Taking the 21-6-9 high-strength stainless steel tube of 15.88 mm × 0.84 mm (outer diameter × wall thickness) as the objective, the multi-parameter sensitivity analysis and three-dimensional finite element numerical simulation are conducted to address the effects of process parameters on the springback behaviors in 21-6-9 high-strength stainless steel tube numerical control bending. The results show that (1) springback increases with the increasing of the clearance between tube and mandrel C_m, the friction coefficient between tube and mandrel f_m, the friction coefficient between tube and bending die f_b, or with the decreasing of the mandrel extension length e, while the springback first increases and then remains unchanged with the increasing of the clearance between tube and bending die C_b. (2) The sensitivity of springback radius to process parameters is larger than that of springback angle. And the sensitivity of springback to process parameters from high to low are e, C_b, C_m, f_b and f_m. (3) The variation rules of the cross section deformation after springback with different C_m, C_b, f_m, f_b and e are similar to that before springback. But under same process parameters, the relative difference of the most measurement section is more than 20% and some even more than 70% before and after springback, and a platform deforming characteristics of the cross section deformation is shown after springback.

Keywords

Springback 21-6-9 high-strength stainless steel tube numerical control bending sensitivity analysis finite element simulation cross section deformation

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References

Wang

Cao

JL.

0Cr21Ni6Mn9N high temperature resistance stainless steel and its application in ramjet. J Propul Tech 1985; 6(4): 80–87.

Tang

NC.

Plastic-deformation analysis in tube bending. Int J Pres Ves Pip 2000; 77(12): 751–759.

Zhang

LL.

Calculation of springback in pipe bending. Forg Stamp Technol 2002; 27(3): 37–39.

Al-Qureshi

Russo

Spring-back and residual stresses in bending of thin-walled aluminum tubes. Mater Design 2002; 23(2): 217–222.

Liu

YF.

Springback and time-dependent springback of 1Cr18Ni9Ti stainless steel tubes under bending. Mater Design 2010; 31(3): 1256–1261.

Zhang

Zeng

et al . Bendability of the wrought magnesium alloy AM30 tubes using a rotary draw bender. Mater Sci Eng A 2008; 486(1–2): 596–601.

Shi

Yang

et al . Springback law of thin-walled 6061-T4 Al-alloy tube upon bending. Trans Nonferrous Met Soc China 2012; 22(Suppl. 2): s357–s363.

Liu

Tang

Ning

RX.

The experimental study on the springback and BP NN prediction model of NC rotary-bending of tube. J Plasticity Eng 2009; 16(6): 85–89.

Yang

Zhan

et al . Research on the springback of thin-walled tube NC bending based on the numerical simulation of the whole process. Comp Mater Sci 2008; 42(4): 537–549.

10.

Yang

Song

et al . Springback characterization and behaviors of high-strength Ti-3Al-2.5V tube in cold rotary draw bending. J Mater Process Technol 2012; 212(9): 1973–1987.

11.

Yang

Tian

et al . Geometry-dependent springback behaviors of thin-walled tube upon cold bending. Sci China Technol Sci 2012; 55(12): 3469–3482.

12.

Sözen

Guler

Bekar

et al . Investigation and prediction of springback in rotary-draw tube bending process using finite element method. Proc IMechE, Part C: J Mechanical Engineering Science 2012; 226(12): 2967–2981.

13.

Zhan

Zhai

Yang

Springback mechanism and compensation of cryogenic Ti alloy tube after numerically controlled bending. Trans Nonferrous Met Soc China 2012; 22(Suppl. 2): s287–s293.

14.

Jiang

Yang

Zhan

et al . Coupling effects of material properties and the bending angle on the springback angle of a titanium alloy tube during numerically controlled bending. Mater Design 2010; 31(4): 2001–2010.

15.

Fang

Wang

et al . Theoretical calculation and FE analysis of springback for 21-6-9 high strength stainless steel tube during NC bending. China Mech Eng 2015; 26(3): 379–384.

16.

Zhang

Zhan

Huang

et al . Sensitivity analysis of material parameters on spring-back of NC bending of high-strength TA18 tube. Adv Mater Res 2012; 472–275: 1003–1008.

17.

Behrouzi

Dariani

Shakeri

Tool shape design in the sheet bending process by inverse analysis of springback. Proc IMechE, Part B: J Engineering Manufacture 2009; 223(10): 1331–1340.

18.

Lajarin

Marcondes

PVP

. Influence of process and tool parameters on springback of high-strength steels. Proc IMechE, Part B: J Engineering Manufacture 2015; 229(2): 295–305.

19.

Choudhury

Ghomi

Springback reduction of aluminum sheet in V-bending dies. Proc IMechE, Part B: J Engineering Manufacture 2014; 228(8): 917–926.

20.

Chen

LZ.

Robust design. Beijing, China: China Machine Press, 2000, pp. 11–15.

21.

Fang

Wang

et al . Effect of mandrel on cross-section quality in numerical control bending process of stainless steel 2169 small diameter tube. Adv Mater Sci Eng 2013; 2013: 849495 (9 pp.).

22.

Fang

Wang

et al . Effect of bending speed on forming quality of 0Cr21Ni6Mn9N stainless steel tube NC bending. Adv Mater Res 2014; 1015: 198–202.

23.

Liu

et al . Work-hardening behavior of 0Cr21Ni6Mn9N austenitic stainless steel. J Iron Steel Res 2005; 17(4): 40–44.

24.

Study on wrinkling behaviors under multi-die constraints in thin-walled tube NC bending. PhD Thesis, Northwestern Polytechnical University, Xi’an, China, 2007.

25.

RJ.

Study on springback of thin-walled tube NC bending. PhD Thesis, Northwestern Polytechnical University, Xi’an, China, 2008.

26.

Jiang

ZQ.

Deformation laws of medium-strength titanium alloy thick-walled tubes in NC bending processes. PhD Thesis, Northwestern Polytechnical University, Xi’an, China, 2010.