Unformatted text preview: REVIEW QUESTIONS 1 "WWW" It ‘1'" Q 13.1 What is the difference between a plate and a
sheet? 13.2 Define (a) roll gap, (b) neutral point, and (c) draft. 3.?) What factors contribute to spreading in flat
mg? 13.\4\ Explain the types of deﬂection that rolls undergo. 13.5 Describe the difference between a bloom, a slab,
and a billet. 13.6 Why may roller leveling be necessary?
13.7 List the defects commonly observed in ﬂat rolling. QUALITATIVE PROBLEMS . 13.8 What are the advantages of tandem rolling?
Pack rolling? /;=‘—"’\
(133$ Make a list of some parts that can be made by \(ETSfiape rolling and (b) thread rolling.
13.10 How are seamless tubes produced? 1:11 Why is the surface finish of a rolled product
‘bett‘efin cold rolling than in hot rolling? 13.12 What is a Sendzimir mill? What are its important
features? 13.13 What typically is done to make sure the product
in ﬂat rolling is not crowned? ——-~————————-————-~——l—-—————~—————~——~—~——m~w.._m_ 3.14 Explain why the rolling process was invented
and developed. \IIEE Flat rolling reduces the thickness of plates and
s eets. It is possible, instead, to reduce their thickness
by simply stretching the material. Would this be a feasible
process? Explain. 13.16 Explain how the residual stress patterns shown
in Fig. 13.9 become reversed when the roll radius or
reduction-per—pass is changed. 13.17 Explain whether it would be practical to apply
the roller-leveling technique shown in Fig. 13.7 to thick
plates. 13.18 )Describe the factors that inﬂuence the magniv
the roll force, F, in Fig. 13.2c. QUANTITATIVE PROBLEMS 1 13.30 Using simple geometric relationships and the
[inclined-plane principle for friction, prove Eq. (13.1). [I/ roll/radius is 200 mm, and it rotates at 200 rpm. (13.321) In Example 13.1, calculate the roll force and wet for the case in which the workpiece material
is 1100—0 aluminum and the roll radius R is 10 in. I 13.3111 Estimate the roll force, F, and the torque for an
551514020 carbon—steel strip that is 200 mm wide and
10 mm thick and rolled to a thickness of 7 mm. The 13.19 Explain how you would go about applying
front and back tensions to sheet metals during rolling.
How would you go about controlling these tensions? 13.20 We noted that rolls tend to flatten under roll
forces. Describe the methods by which flattening can
be reduced. Which property or properties of the roll
material can be increased to reduce flattening? @ It was stated that spreading in ﬂat rolling in— $re5§2s with the (a) decreasing width-to-thickness ratio
of the entering material, (b) decreasing friction, and
(c) decreasing ratio of the roll radius to the strip thick-
IngugExplain why. 33.22 As stated in this chapter, ﬂat rolling can be can
fiedﬁﬁt by front tension only, using idling rolls (Steck; 13.33 Calculate the individual drafts in each of the
stands in the tandem—rolling operation shown in
Fig. 13.11. 13.34 Assume that you are an instructor covering the
topics described in this chapter, and you are giving .2
quiz on the numerical aspects to test the understanding
of the students. Prepare two quantitative problems anc
supply the answers. ...
View Full Document
- Spring '08