elena trifonova presentation-project 015

May 2, 2023 Page 1

Project Scope Plus Preliminary Specification

Covering The Design Of

The Four High Temper Mill

Presented By Elena TrifonovaBluetip Engineering Consulting Inc.

March 24, 2012

May 2, 2023 Page 2

Design Team Group 1

Team members are:

• Elena• Clair• Jane

Assigned To Design The Mill Housing Assembly

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PROJECT BACKGROUND

Bluetip Engineering Consulting Inc is requested to design and supply a four high mill stand. This machine will have the capability to temper roll hot band steel coils and cut the coils to a specified length.

The main function of the machine is to improve material elongation and thus minimizing material cracking problems such us Leuder Lines.

There are secondary improvements in areas of shape, gage, tolerances and surface finishing.

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Four High Temper Mill

The Four High Skin Pass Millis designed for Nova Steel Limited by Bluetip Engineering

Consulting Inc. for the purpose of cold temper rolling of hot

band steel strip coils.

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Machine System Overview

This mill design will incorporate the latest technology for system performance, reliability, and control including: Hydraulic screw-down system for AGC control, work roll positive bending system to control the product flatness over full product range, and a roll quick change system.

The Mill is designed for heavy duty industrial use and will sustain year round operation.

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Machine System Requirements

• Maximum rolling load- 1600 tons (72”w x 0.50” thick material, 2.5% elongation, rolled at 85 fpm with an assumed friction coefficient of 0.3)

• Hydraulic screw-down force- 1800 tons• Power- 500 hp• Maximum roll bending- 70 tons• Backup roll diameter- 40” max, 37” min• Backup neck diameter- 22”• Backup roll neck length- 23”• Work roll diameter – 18” max. 16 “ min.• Work roll neck diameter- 10.5”• Work roll and backup roll barrel length-80”

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Major Sections Of The Machine System

• Four high roll stand complete with work and back-up rolls and roll chocks, work roll bending, hydraulic screw-down chock clamping

• Quick Roll Change System• Combination Reduction Gearbox And Pinion Stand• Roll Drive Spindles• Spindle Support

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Roll Material Specifications

• Material : Hot band strip steel, some pickled and oiled

• Material Grade : Yield stress up to 70 ksi

• Strip width range : 72 inches maximum, 26 inches minimum

• Strip thickness range: Carbon steel: 1/2 inch maximum, HSLA Steel: 1/4” maximum, 0.060 inch minimum

• Elongation: 2.5 percent maximum for carbon steel, 2 percent for HSLA steel

• Rolling speed : 150 fpm maximum

• Product Rolling Temperature : Ambient

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Strength calculation for vertical stress in closed-top housing

L1

M1

L2

M2

PL1 4

I1

I3

I2

L1 2

P12

M1

• L1, L2 and L3- are the length of the crossbeams and the posts along the neutral line

• I1, I2 and I3- are the moments of inertial of the top cross beam, the posts and the bottom cross beam

• M1-bending moment in the cross beam

• M2-bending moment in the post• P1-half the force of P in this

cross section on each branch of the housing = 1800/2=900 tons

P1

P1

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The horizontal force with identical moments of inertia of the top and bottom beams we will not consider since they differ little from one another

1

3 31

1

* 18*36 69,98412 12

B HI

3 32 2

2* 18*20 12,00012 12

B HI

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W1- modular section of bending in the cross beamW2- modular section of bending in the post

21 1

1* 18*36 3,8886 6

B HW

2 22 2

2* 18*20 1,2006 6

B HW

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Assume I1=I3 , due to symmetrical relative to the vertical and horizontal axis:

1 2

1 1 1 21

1 2

1 2

87 222( ) ( ) ( ) ( )* 900*2000*872* 2*69,984 12,000* * 87 2224 4 ( ) ( )( ) ( ) 69,984 12,000

L LP L I IM L L

I I

1 37,917,381M

May 2, 2023 Page 13

1 12

2 1

1 2

* 1 900*2000*87 1* ** 222*69,9848 8 1 ( )1 ( ) 87*12,000*

P LM L IL I

2 1,232,553M

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1max

1

37,917,381 9,7523,888

MBeamW

1 2max

2 2

900*2000 1,232,553 2,500 1,027 35272 2*18*20 1200P MPostF W

PSI

PSI

Normal Stress Calculation For Cross Beam And Post :

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Safely Factor Calculation:

22

70,000 19.853,527

bSf

Tensile strength of the material ASTM 27 Grade 70-40 cast steel

Max normal (principal) stress on the post

2 10Sf The design meets the minimum safety factor requirement of

10 x.

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The design meets the minimum safety factor

requirement of 10 x

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Simulation Study - Static Stress Yield strength

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Factor of Safety (Max von Mises Stress)=10

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Mill Housing Assembly

• Mill Housing System Consists Of:• Housing Weld Assembly• Middle Blocks• Work Roll Chock End Stops • Back-up Roll End Stops• Hydraulic Screw-down Cylinders• Work Roll Bending Cylinders• Top Roll Balance Cylinders

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Mill Housing Assembly

• Mill Housing System Consists Of:• Mill Housing Weld Assembly• Middle Blocks• Work Roll Chock End Stops • Back-up Roll End Stops• Hydraulic Screw-down System• Work Roll Bending System• Top Roll Balance Cylinders

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Mill Housing Assembly

• Mill Housing System Consists Of:• Mill Housing Weld Assembly• Middle Blocks• Work Roll Chock End Stops • Back-up Roll End Stops• Hydraulic Screw-down System• Work Roll Bending System• Top Roll Balance Cylinders

May 2, 2023 Page 23

Mill Housing Assembly

• Mill Housing System Consists Of:• Mill Housing Weld Assembly• Middle Block• Work Roll Chock End Stops • Back-up Roll End Stops• Hydraulic Screw-down System• Work Roll Bending System• Top Roll Balance Cylinders

May 2, 2023 Page 24

Mill Housing Assembly

• Mill Housing System Consists Of:• Mill Housing Weld Assembly• Middle Blocks• Work Roll Chock End Stops • Back-up Roll End Stops• Hydraulic Screw-down System• Work Roll Bending System• Top Roll Balance Cylinders

May 2, 2023 Page 25

Mill Housing Assembly

• Mill Housing System Consists Of:• Mill Housing Weld Assembly• Middle Block• Work Roll Chock End Stops • Back-up Roll End Stops• Hydraulic Screw-down System• Work Roll Bending System• Top Roll Balance Cylinders

May 2, 2023 Page 26

Mill Housing Assembly

• Mill Housing System Consists Of:• Mill Housing Weld Assembly• Middle Block• Work Roll Chock End Stops • Back-up Roll End Stops• Hydraulic Screw-down System• Work Roll Bending System• Top Roll Balance Cylinders

May 2, 2023 Page 27

Housing Frame Weld Assembly

Consists of two housing sides which are constructed separately and connected together using top and bottom beams.

Once welded together and rough machined, the Housing Weld Assembly is annealed for stress relief before final machining.

Raw Material Used is: Steel Casting ASTM 27 Grade70-40

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Housing End Weld Assembly

• Material: Steel Casting• Additional Parts Shown

• Lift Trunion• Plate• Gusset

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Middle Block

The middle blocks are located one on each side of the Mill Housing windows; serve as vertical guides for the work rolls chocks.

The middle blocks are bored, drilled and tapped for the roll bending and back-up roll balance Cylinders, and the work roll end

stop guide pins

The middle block material is AISI C1045

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Back-up Roll End Stops

The end stops lock the operator side back-up roll chock assemblies into the roll housing.

There are two end stops per chock assembly one at each side of the operator’s side housing.

End stop data is as follows:-Lock plate: fabricated and machined from steel plate; drilled for stop guide pins and cylinder rod-end pin-Cylinder: Parker

May 2, 2023 Page 35

Hydraulic Screw-down Cylinders• The screw-down system is used to

obtain and hold the gap between the rolls so that a constant and accurate strip thickness can be held

• Screw-down cylinders:• -Bore: 26”• -Stroke: 10”• -Rod: 16”• -Operating pressure: 3,200 PSI• -Test pressure: 6,000 PSI• -Fluid hyd. Oil: mineral based • -Speed: 10” per min• -C/W LVDT - Tempo Sonics• -Relieve valve settings: 3,600 PSI

for normal operation, 4,000 PSI for special rolling requirements

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Work Roll Bending Cylinders

• located in the middle block • Bore: 5.125”• -Stroke: 4.25”• -Rod: 4.25”• -Operating pressure:

4,000 psi

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Top Roll Balance Cylinders• located in the middle block• -Bore: 2.5”• -Stroke: 5”• -Rod: 2”• -Operating pressure:

4,000 PSI• -Test pressure: 6,000 PSI• -Extended retraction speed: • -Rolling with gap control:

10” per min• -Roll gap set-up:

2.5” per min

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Top Beam

• Fabricated From Steel Plate

• Welded Assembly

• Stress Relieved Before Final Machining.

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Bottom Beam

• Fabricated From Steel Plate

• Welded Assembly

• Stress Relieved Before Final Machining.

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Mill Support Plate

• Located On The Top Of The Mill Foundation

• Fabricated Weldment• Machined To Accept

The Mill Housing Feet• Drilled For Foundation

Bolts • Drilled For The Mill

Housing Holding Down Bolts.

• Manufactured From ASTM A36 steel.

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Load Block Assembly

• Functions As Top Back-Up Roll Hard Stop

• Attached To Underside Of Top Beam

• Load Block Is Constrained By Two Endplates

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My Project Role And Participation

• Took The Lead To Design The Mill Stand Complete With Most Associated Major Drawings

• Collaborated With My Team Mates On The Balance Of The Project• Sub-level Drawings• Project Requirements Document• Project Presentation• Engineering Calculations