Design Project Page | 1
MAE 3123 Manufacturing Processes
Design Project
Submission Date: November 19, 2015
Team Members and Respective Tasks:
❖ Hayden Dannels
❖ Bryce Guyer
o Calculated Entering and Exiting Velocities
o Helped determine the percent reduction per pass
❖ Raymond McVay
✓ Contributed to Roll Force calculations
✓ Formatted, edited paper
❖ Justin Weyand
✓ Generated Final Graphs
✓ Helped write and edit paper
Design Project Page | 2
1.0 Introduction
Hot rolled AISI 304 stainless steel sheets 32” wide are to be reduced from 9 to 30
gauge while maintaining a constant width. Design will be based on tandem rolling
operation without intermediate annealing. The goal of this project is to design a robust
manufacturing process that fulfills all design requirements in geometry, thermal
properties, lubricants, and velocities.
2.0 General Design
Understanding we needed to reduce thickness, we initially researched actual
dimensions for 9 and 30 gauge to calculate total required reduction. We found 9 and 30
gauge to be .1495 inches and .012 inches, respectively [5]. This is a total reduction of
roughly 90%. Researching common processes for sheet gauge reduction, we
considered cold rolling.
2.1 Determination of Rolling Process
Cold rolling allows for a total reduction varying from 50-90% while increasing
strength and surface finish. Cold rolling usually require multiple rollers, typically ranging
from 10-30 inches in radius, and multiple passes allowing roughly 20–40% reduction per
pass [2]. Taking these factors into consideration, we designed a cold rolling process
entailing 8 passes on 10 inch radius rollers, with a 27% reduction per pass. This
reduction per roller can be calculated by Equation 1 and is organized in Table 1 below:
ℎ𝑓=ℎ𝑜(1−27%)
Inches
Roller
h0
hf
1
0.1495
0.1091
2
0.1091
0.07957
3
0.07957
0.05816
4
0.05816
0.04246
5
0.04246
6
0.03099
7
0.02262
Design Project Page | 3
Equation 1: hf Calculation Table 1: 27% Reduction per Roller
2.2 Velocities
The velocities of the sheet after each roller is important in determining the
residual stresses in the sheet, and the power to spin the rollers. While researching
normal radial velocities of the sheet, we solved problem 6.102 from BOOK NAME in
order to find a value for the initial velocity. Using a similar initial velocity, and the change
in thickness of the sheet due to each roller (found in Equation 1), we were able to
determine the resulting velocities before and after each roller shown in Table 2 using
Equation 2:
Next, we calculated radial velocities (RPM) of each roller shown in Table 3
through Equation 3, by relating velocity () and the circumference of the rollers ()[2].
8
0.01652
voho = vfhf
(Equation 2)
ft/s
Roller
v0
vf
1
5
6.8515
2
6.8515
9.3940
3
9.3940
12.8525
4
12.8525
17.6050
5
17.6050
24.1205
6
24.1205
33.0460
7
33.0460
45.2480
8
45.2480
62.2915
Table 2: Entering and Exiting Velocities
Design Project Page | 4
2.3 Standard Industry Velocities
In order to determine if these radial velocities are obtainable, we compared them
to a range of velocities that were found experimentally [6]. Once we found a range of
normal radial velocities for the rollers to be around 30-480 RPM, we determined that our
initial findings would not be sufficient. In order to solve this problem, we decided to
𝑅𝑃𝑀 = 𝑉
2𝜋𝑟 (Equation 3)
RPM
Roller
Radial Velocity
1
78.51
2
107.65
3
147.28
4
201.74
5
276.40
6
378.68
7
518.50
8
713.81
Table 3: Radial Velocities