EML4321 Quiz 4

Which of the following shows distribution of die pressure P/Sy’ in plane-strain compression with sliding friction?

• a

• b

Figure 1 shows standard terminology for various features of a typical forging die. Which one of the following correctly identifies the features (A), (B), and (C)?

• (A) Flash, (B) Gutter, (C) Land

• (A) Flash, (B) Land, (C) Gutter

• (A) Land, (B) Flash, (C) Gutter

• (A) Land, (B) Gutter, (C) Flash

True or False? In rolling, the directions of the net friction force and the surface velocity of the roll must be different.

• True

• False

Which of the following correctly describes the rolling operation.

• At the neutral point, the roll moves faster than the workpiece.

• To the left of the neutral point, the workpiece moves faster than the roll.

• To the left of the neutral point, the roll moves faster than the workpiece.

• To the right of the neutral point, the roll moves faster than the workpiece.

True or False? As friction increases in the rolling operation, the neutral point shifts toward the exit.

• True

• False

In rolling, increasing the friction between the roll and strip does which of the following?

• decreases the maximum angle of acceptance but increases the maximum draft.

• decreases both the maximum angle of acceptance and maximum draft.

• increases the maximum angle of acceptance but decreases the maximum draft.

• increases both the maximum angle of acceptance and maximum draft.

Which type of thread is stronger: (a) rolled thread or (b) machined thread?

• rolled thread

• machined thread

Which of the following approaches can be used to reduce the rolling force? (two correct answers)

(a)  applying front and/or back tension

(b)  taking higher reduction per pass

(c)  using larger diameter rolls

(d) reducing friction

• (a) and (b)

• (b) and (c)

• (c) and (d)

• (d) and (a)