Investigations on relations between shape defects and thickness profile variations in thin flat rolling

Moazeni, Babak; Salimi, M.

doi:10.1007/s00170-014-6544-6

Cited by 46 publications

(20 citation statements)

References 18 publications

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“…The actual rolling operation, however, keeps the ratio crown changing just within an acceptable range such that the cross‐sectional profiles of a strip entering and leaving a roll gap are geometrically similar. This acceptable range of ratio crown variations that does not cause flatness defects is known as the “flatness deadband.” According to the geometric condition of maintaining good flatness, flatness deadband is positively related to the thickness of strip, and a thinner strip means a smaller ratio crown variation for desired flatness. With a coil of strip rolling in the tandem cold mill, the thickness of the strip in the roll gap gradually decreases from the upstream to the downstream stand.…”

Section: Flatness Control Strategy Of a Five‐stand Tandem Cold Millmentioning

confidence: 99%

Numerical Analysis of Intermediate Roll Shifting–Induced Rigidity Characteristics of UCM Cold Rolling Mill

Wang

Ling

et al. 2018

steel research int.

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The present investigation devises a flatness control strategy for a five‐stand tandem cold rolling mill. In addition, intermediate roll shifting (IRS)–induced rigidity characteristics of the six‐high Universal Crown Control mill (UCM mill) as a key model for the automatic thickness and flatness control systems are established. A three‐dimensional elastic‐plastic finite element analysis for a strip rolling process is conducted when the UCM mill is subjected to different IRS values. The convergence and precision of the simulation model are verified using experimental data in a five‐stand tandem cold rolling line. Through a steady‐state rolling analysis of the process, the vertical and transverse rigidity characteristic curves of the roll‐stack, reduction strain field of the strip, variation in strip crown, elastic deflection of the rolls, and contact stress field between rolls are extracted. The results show that the IRS obviously changes the deflection curves of the rolls and then causes the variations in the exit thickness and transverse thickness difference of the strip. The nonuniform stress distribution between rolls caused by the increasingly IRS value lead to local stress concentration on the side of the roll. A mechanism for the effect of IRS on the rigidity characteristics of the mill is presented and discussed.

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Section: Flatness Control Strategy Of a Five‐stand Tandem Cold Millmentioning

confidence: 99%

Numerical Analysis of Intermediate Roll Shifting–Induced Rigidity Characteristics of UCM Cold Rolling Mill

Wang

Ling

et al. 2018

steel research int.

View full text Add to dashboard Cite

show abstract

“…In order to acquire the corresponding results, the length of strip model needs to be set as 15–20 times of the roll gap length and the calculation efficiency is very low. Considering the characteristic of steady rolling period, the length of strip model can be reduced to 5–6 times of the roll gap length by imposing the transverse uniformity of the strip longitudinal displacement at the end faces, remarkably decreasing the grid number and increasing the calculation efficiency.

σ_{ϕ} = σ_{0} \exp (- 2.923 T + 3.721) {(\frac{\dot{ϵ}}{10})}^{(0.3102 T - 0.2659)} \times true[1.52 {true(\frac{ϵ}{0.4} true)}^{0.4554} - (1.52 - 1) \frac{ϵ}{0.4} true]

…”

Section: Flatness Evolution Of Strips With Different Thickness Duringmentioning

confidence: 99%

Flatness Analysis and Control of Strips with Different Thickness in 2250 mm Hot Tandem Rolling

Chai

Zhang

et al. 2018

steel research int.

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Aiming at the flatness difference between thick strip and thin strip under the same flatness control strategy on a 2250 mm hot tandem rolling line, a flatness calculation model is firstly established in this paper. With the unknown variable–transversal flow of metal solved by finite element methods, the flatness calculation model is used to analyze and compare the flatness and longitudinal residual stress evolution during thick strip and thin strip rolling. The result shows that under the premise of the constant exit relative crown in the downstream stands, the distribution of metal transversal flow due to larger reduction ratio in F2 and F3 stand causes the flatness of thin strip differing much from that of thick strip. In order to improve the flatness quality, a crown setup method is proposed. Based on the relationship among the distribution of metal transversal flow, entry relative crown, and the change of relative crown obtained from the finite element model, the exit crown of thin strip at each stand is optimized by genetic algorithm with a restriction of achieving the target crown at exit of F7 stand and a goal of good flatness quality during rolling.

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“…FEM is used for residual stress analysis in many elasticplastic forming process and is proved to be the most suitable method [20,21]. Therefore, FEM was chosen for modeling analysis of roll tensioning process.…”

Section: -D Fem Model For Calculation Of Tensioning Stressmentioning

confidence: 99%

Research on the effect of yield strength of circular saw blade on roll tensioning process

Zhang

2016

J Wood Sci

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In this paper, a 2-D and 3-D finite element model of roll tensioning process of circular saw blade were established by Static/General module of ABAQUS software based on finite element method. The rolling force and tensioning stress distribution of circular saw blade were calculated by these two models which were proved to be true and reliable. The effects of yield strength of circular saw blade on tensioning stress distribution and rolling force were studied. The research achievements showed that a circular saw blade made with high yield strength obtained a higher tangential compressive stress and radial compressive stress in the rolled region during roll tensioning process, which has both advantages and disadvantages for the stability of the saw blade. Besides, a circular saw blade made with high yield strength also put forward higher requirements for roll tensioning equipment because of the large rolling force during roll tensioning process.

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Investigations on relations between shape defects and thickness profile variations in thin flat rolling

Cited by 46 publications

References 18 publications

Numerical Analysis of Intermediate Roll Shifting–Induced Rigidity Characteristics of UCM Cold Rolling Mill

Numerical Analysis of Intermediate Roll Shifting–Induced Rigidity Characteristics of UCM Cold Rolling Mill

Flatness Analysis and Control of Strips with Different Thickness in 2250 mm Hot Tandem Rolling

Research on the effect of yield strength of circular saw blade on roll tensioning process

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