Effect of process parameters on steel tube roundness in straightening process

Ma, Liye; Du, Yukang; Meng, Zhijuan; Ma, Lifeng; Liu, Zijian

doi:10.1007/s42243-020-00497-8

“…This method makes the ram gradually progresses by controlling the increment, and gradually increases the surface stress, which not only avoids the situation of over bending, but also effectively captures the maximum stress of the part between the yield strength and tensile strength so that can realize both part be straightened and crack avoidance. In view of the powerful analysis and simulation functions of finite element simulation software, more and more researches use finite element analysis software to guide the straightening process and achieve good results [21][22][23][24]. By simulating the stress state during the straightening process, it can provide strong support for the selection of punch position during straightening.…”

Section: Online Crack Detection Systemmentioning

confidence: 99%

Study on cracks and process improvement for case hardened gear shaft straightening

Ma

¹

,

Shen

²

,

Xu

³

2022

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Gear shaft is one of the key components for transmitting torque and speed in automotive transmission. Deflections will inevitably occur after heat treatment. It is necessary to ensure the straightness of the parts by straightening. During straightening process, cracks often appear and result in scrapped parts. This paper focuses on the situation of high straightening crack rate of internal input shaft in one dual-clutch automotive transmission, makes an in-depth analyses the pressure straightening process theory, crack generation mechanism, working process and crack detection system. After studying on the case hardened gear shaft material properties, elastoplastic process theoretical basis, crack characteristic and finite element simulation, etc., This paper has systematically improved straightening crack performance and proposes three crack rate improvement methods by using finite element analysis to find out optimal punch point which can reduce the maximum stress value; increasing the punch increments and adopt vector straightening to improve the straightening procedure; reducing the gas quenching pressure in the heat treatment process to improve the mechanical properties of the parts, etc. Finally, the scrap rate of straightening crack was reduced from 1.95% to 0.14%.

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“…In view of the powerful analysis and simulation functions of finite element simulation software, more and more researches use finite element analysis software to guide the straightening process and achieve good results [21][22][23][24]. By simulating the stress state during the straightening process, it can provide strong support for the selection of punch position during straightening.…”

Section: Finite Element Analysis and Improvement Of The Position Of Tmentioning

confidence: 99%

Study on cracks and process improvement for case hardened gear shaft straightening

Ma

¹

,

Shen

²

,

Xu

³

2021

Preprint

View full text Add to dashboard Cite

Gear shaft is one of the key components for transmitting torque and speed in automotive transmission. Deflections will inevitably occur after heat treatment. It is necessary to ensure the straightness of the parts by straightening. During straightening process, cracks often appear and result in scrapped parts. This paper focuses on the situation of high straightening crack rate of internal input shaft in one dual-clutch automotive transmission, makes an in-depth analyses the pressure straightening process theory, crack generation mechanism, working process and crack detection system. After studying on the case hardened gear shaft material properties, elastoplastic process theoretical basis, crack characteristic and finite element simulation, etc., This paper has systematically improved straightening crack performance and proposes three crack rate improvement methods by using finite element analysis to find out optimal punch point which can reduce the maximum stress value; increasing the punch increments and adopt vector straightening to improve the straightening procedure; reducing the gas quenching pressure in the heat treatment process to improve the mechanical properties of the parts, etc. Finally, the scrap rate of straightening crack was reduced from 1.95% to 0.14%.

show abstract