Rolling Mill Roll Pass Design

Roll pass design  Contact Angle  Contact Angle  When stock size is entry in pair of roll ,  then where first time stock size touches to roll in the running position after that stock acrosses center position of roll then one angle created between frist stock touch and center touch ,    it is called contact angle Read more Roll pass design spread and elongation Here A and B are contact Angle Read more Angle of bite Section weight The oversize the co-efficient among section and roll , the oversize potential angle of bite Following formula can be  applied for contact Angle  Read more Type of rolling mill Section Area Read more   Roll pass design Draft  Vinay Kumar YouTube Channel link

Bite of Angel We should know bite of angle in Roll pass design  Bite of angle is a most important topic in Rolling , bite of angle used for selection roll diameter Acroding to stock size and temperature  Bite of angle Calculated by following formula Where  d = Draft  R = Roll Radius

Reduction Reduction is the reduce in area from stand pass to stand pass and it manifested as a percentage of the entry stock area  [( A in - Aout) / A in ] × 100 Average reduction of whole mill calculate by it formula [1- 1/ (√n( A in / A out ) ] × 100 = R ave  Reduction and elongation  calculated by following Formula [1- ( 1 / E )] ×100 = R  General reduction and elongation [1- ( 1 / E ave)] × 100 = R ave

Spread and elongation Speard :- when the steel ( section) compressed in the roll it is  move in free space in rolling passes  it called spread , in case plastic deformation apply here  Here some formula for calculate spread  Spread displayed by - ∆b 1-  ∆b = (∆h × b in ×√( b in × R n )) / (3 × ( b in^ + (   h in × h out)) 2- ∆b = 0.66 × (∆h/ h in+ h out) × √(∆h × R n)) Where:-  n   = new roll diameter Rn= new roll radius Elongation Elongation is percentage of tension from section to point of failure Formula of calculate elongation Ain / Aout = Et Where:-  Ain =  Entry steel ( section) cross sectional area  Aout = Exit steel( section ) cross sectional area  Et  =  total elongation Average elongation  n√( Ain / Aout ) = Eave  Where:-  n = number of passes  Ea = average elongation

We will explain What is draft in Rolling pass design Draft is the Reduction in section height , when section entry in Roll pass and section exit from Roll pass  or which section Reduce between entry height and exit height  that is called draft  h in - h out = Da = ∆h h in    = entry height of stock ( section)  h out =delivery height of stock ( section)  D      = abusulet draft Percentage(%)Draft between entry heigh of stock and delivery height of stock  D r = percentage (%) draft  [( h in -  h out)/ h in] × 100 = D r  

Section Area 1:- Square Area = Side × Side  2:- Ovel Area     = a × b ×  3.1428571429 https://svinaykumar1987.blogspot.com/2021/09/roll-pass-design-number-of-passes.html 3:- Round Area =   3.1428571429 × r × r  https://svinaykumar1987.blogspot.com/2021/08/roll-pass-design-for-continuous-bar-mill.html 4:- Rectangular Area = L × W