Study on the pre-shearing cropping process of steel bars

  • C. L. Hu
  • L. Q. Chen
  • Zhen Zhao
  • J. W. Li
  • Z. M. Li


A new type of bar-cropping process, termed the pre-shearing cropping process, which can improve billet cross-section quality has been proposed in this study. The new cropping process was realized by using a servo-controlled press. A low-carbon steel 20Cr as-received and a medium-carbon steel SCM435 as-annealed were used to test the process. A group of pre-shearing cropping experiments was carried out with different pre-shearing values of 6.67, 13.33, 20.00, and 26.67% under a pre-shearing speed of 10 mm/s and a cropping speed of 600 mm/s, and conventional cropping experiments with different cropping speeds of 200, 400, and 600 mm/s were conducted for comparison. The quality of the cropped billets was evaluated quantitatively using the indices of surface flatness, ovality, and incline angle. The effect of cropping speed on the conventional process and the effect of pre-shearing on the pre-shear cropping process were investigated in detail. The experimental results showed that the pre-shearing cropping process could improve the quality of the cropped billets and reduce the maximum cropping load slightly compared with the conventional cropping process. Finally, the mechanism of the pre-shearing cropping process was furtherly analyzed by finite element simulation and tried to be summarized.


Pre-shearing Cropping process Surface Flatness Ovality Incline angle Billet Forming load 


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Funding information

This work was supported partially by the National Natural Science Foundation of China (grant number 51475294).


  1. 1.
    Organ AJ, Mellor PB (1967) Some factors affecting the quality of cropped billets. Int J Mach Tool Manu 7(4):369–389CrossRefGoogle Scholar
  2. 2.
    Das MK, Sadollah ZT (1980) Cropping billets with low aspect ratios. Proceedings of the Twentieth International Machine Tool Design and Research Conference, Palgrave Macmillan UK, pp 195–202Google Scholar
  3. 3.
    Chen JD, Yu DH, Wang YW, Zhang ZG (1992) Plastic precision cropping of metal materials. Int J Mach Tool Manu 32(3):425–433CrossRefGoogle Scholar
  4. 4.
    Chen JD, Wang YW, Yu DH, Zhang ZG (1992) Brittle precision cropping of metal materials. Int J Mach Tool Manu 32(3):415–424CrossRefGoogle Scholar
  5. 5.
    Zhao SD, Wang J, Wang LH, Hua CJ, He YP (2005) Iterative learning control of electro-hydraulic proportional feeding system in slotting machine for metal bar cropping. Int J Mach Tool Manu 45(7):923–931CrossRefGoogle Scholar
  6. 6.
    Zhang LJ, Zhao SD, Hua CJ, Guo CF, Lei J (2008) Investigation on a new type of low-stress cropping system with variable frequency vibration. Int J Adv Manuf Technol 36(3–4):288–295CrossRefGoogle Scholar
  7. 7.
    Tang Y, Zhao SD, Wang ZW (2009) A novel type of precision cropping machinery using rotary striking action. P I Mech Eng C - J Mec 223(8):1965–1967CrossRefGoogle Scholar
  8. 8.
    Zhang LJ, Zhao JC (2013) Research of effects of bar geometric parameters on initial external force in precision cropping. Int J Adv Manuf Technol 68(9–12):1919–1925CrossRefGoogle Scholar
  9. 9.
    Zhang LJ, Zhao YR, Wang HX (2015) Investigation on the precision cropping system with high-speed and centrifugal action. Int J Adv Manuf Technol 80(5–8):1311–1317Google Scholar
  10. 10.
    Tang Y, Zhao SD, Lin J (2010) Experimental investigation of the effect of the circumferential loading of a rotary striking action cropping system. P I Mech Eng B - J Eng 224(7):1095–1101Google Scholar
  11. 11.
    Zhang L, Zhao S, Wang Z (2015) Research on radial motion characteristic of the cropping hammer in radial-forging cropping method. Adv Mater Sci Eng 1–8Google Scholar
  12. 12.
    Zhong B, Zhao SD, Zhao RF, Liao JA (2014) Numerical and experimental investigation on the influence of main motor rotational frequency in fine-cropping. P I Mech Eng C - J Mec 228(3):514–524CrossRefGoogle Scholar
  13. 13.
    Zhong B, Zhao SD, Cai B, Zhao XZ, Zhang CW (2016) New controllable and near net bar fine-cropping system. P I Mech Eng B - J Eng 6(1):124–128Google Scholar
  14. 14.
    Zhang LJ, Zhao YR (2013) Theoretical analysis of heat stress prefabricating the crack in precision cropping. J Eng Sci Technol Rev 6(1):124–128Google Scholar
  15. 15.
    Song JL, Li YT, Liu ZQ, Fu JH, Ting KL (2009) Numerical simulation and experiments of precision bar cutting based on high speed and restrained state. Mater Sci Eng A 499(1):225–229CrossRefGoogle Scholar
  16. 16.
    Henry R, Liewald M (2015) High-speed cropping of rods and wire with superposition of various stress conditions. Key Eng Mater 651-653:132–137CrossRefGoogle Scholar
  17. 17.
    Cho TT, Sugiyama S, Yanagimoto J (2016) Effect of process parameters of backward extrusion by servo press on purification of A7075 alloy under the semisolid condition. Mater Trans 57(8):1351–1356CrossRefGoogle Scholar
  18. 18.
    Kaya S (2016) Non-isothermal warm deep drawing of SS304: FE modeling and experiments using servo press. Int J Adv Manuf Technol 83(5–8):1047–1056CrossRefGoogle Scholar
  19. 19.
    Yang M, Shimizu T (2015) High-density energy-assisted micro-forming for fabrication of metallic devices. Mater Manuf Process 30(10):1229–1234CrossRefGoogle Scholar
  20. 20.
    Wei YB, Jin WY, Lang FY (1996) Experimental analysis of stress shearing. J Gansu Univ Technol 22(3):21–27 (In Chinese)Google Scholar
  21. 21.
    Cockcroft MG, Latham DH (1968) Ductility and the workability of metals. J Inst Met 96:33–39Google Scholar
  22. 22.
    Kim JB, Seo WS, Park K (2012) Damage prediction in the multistep forging process of subminiature screws. Int J Precis Eng Manuf 13(9):1619–1624CrossRefGoogle Scholar

Copyright information

© Springer-Verlag London Ltd., part of Springer Nature 2018

Authors and Affiliations

  • C. L. Hu
    • 1
  • L. Q. Chen
    • 1
  • Zhen Zhao
    • 1
  • J. W. Li
    • 1
  • Z. M. Li
    • 2
  1. 1.Institute of Forming Technology and EquipmentSchool of Materials Science and Engineering, Shanghai Jiao Tong UniversityShanghaiChina
  2. 2.Ningbo SiJin Machinery Co. Ltd.NingboChina

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