Individual Effects of Mill Parameters.

a) First intermediate roll position, Figure 27a-c:

From the horizontal and vertical strain gauge results, no pattern is shown which can be related to first intermediate roll position.

The undercut roll gauge results show that alterations in the first intermediate roll position dramatically affect the magnitude of the peak strain. This difference is larger than any other parameter effect under investigation. The strain peak gets wider at its base and the maximum magnitude of strains change with altering first intermediate roll positions. As the point of taper transition is moved towards the centre of the mill then the magnitude and width of the strain peak increases.

b) First intermediate roll profile, Figure 28a-c:

The different profiles under investigation were the standard single taper and a triple tapered roll. Details of the profiles are shown in Figure 28a.

No strain pattern seen can be related to the different roll profiles for. both the horizontal and vertical gauge plots. There is a hint from the horizontal gauge plots that the strain peak is less pronounced but broader in effect with the triple taper. There is also a hint from the vertical results that the plots between the right and left of the mill cross over in a more severe manner.

From the undercut roll gauge results it is seen that, when using the modified triple tapered first intermediate rolls, the stain peak is less severe. The strain peak is also seen to affect less of the strip width, that is, it is narrower.

c) Loading differences, Figure 29a-c:

From the horizontal gauge plots it is shown that with increasing load there is an increase in the values of measured strains.

The plots between the right and left of the mill cross in a more severe manner with increasing loads.

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The vertical gauge plots confirm the trends of the horizontal gauge plots. With increasing loads there is an increase in compressive strain values.

The undercut roll gauge plots reveal that, for increasing loads, there is a steady increase in strains. Peak strain values increase for each increase in load. The width of the strain peak does not alter with load differences.

d) Strip in or out of the roll bite, Figure 30a-d:

The horizontal gauge results show that the strain peaks are different with strip in or out of the roll bite. With strip in the peaks are more pronounced especially at the end of the roll which is not in direct contact with the taper transition of the first intermediate roll. The nature of the peak is not independent but it relates to first intermediate roll profile position, load etc.

Examination of the vertical gauge results shows, with strip in, a higher and altered positioned strain peak. The decrease in strains at the edges of the plots is more severe with strip in.

From the undercut roll strain plots the major difference between strip in or out of the roll bite is that the edge strains reduce in a different manner. With strip in the strains reduce more severely.

e) Work roll profile, Figure 31a-d:

Due to the measuring rolls being parallel ground the effects of work roll profile are limited to one roll being ground with a camber. The only results available at present to show the effects of work roll profile were taken with strip in the mill. With this situation there is a slight masking of the measurable effects of work roll profile on strains.

The horizontal and vertical gauge results show little measurable effects of different roll profiles. There is a trend showing that with flat rolls, there are higher peak compressive strains than with cambered.

From the undercut roll strain results there is no measurable difference on strains due to work roll profile. With the mill set-up used the measuring technique is not sensitive enough to measure the effects of one cambered roll on vertical work roll bending.

f) Saddle settings, Figure 32a-c:

There are no clear effects on the recorded strains of the horizontal, vertical and undercut roll gauge results, due to saddle adjustments (mill loading pattern).

g) Castor differences, Figure 33a-d:

Only horizontal and vertical strain plots are available to show the effects of castor differences on roll bending. There are no clear effects on the recorded strains due to castor differences (work roll support symmetry).

h) Flat ground tapers, Figure 34a-c:

Tests were carried out with a level mill set up, that is, with all of the mill rolls ground V

flat to help in the analysis of parameter results. A set of control results was gained.

The horizontal gauge plots show a level trace. The left and right of the roll strain plots cross over a number of times at the mill centre. At the ends of the mill there is a slight separation of the plots. This separation is in opposite directions for each~side of the mill. The strains on the right of the roll are higher at one side of the mill and vice-versa.

The vertical gauge results show consistent values of compressive strain across the mill. At the mill edges there are slight decreases in compressive strains recorded. There is a separation of the plots seen at the ends of the mill. This confirms the horizontal gauge results.

From the undercut roll strain plots there is a consistent level of strains across the mill. There is only a slight decrease in strains recorded at the mill centre.