Cold Rolling Reduction Calculation Troubleshooting: Negative Signs Explanation

Click For Summary

Discussion Overview

The discussion revolves around the calculation of reduction in the cold rolling process, specifically addressing issues related to negative signs in calculations and the relationship between cold rolling and hardness of metals. The scope includes technical explanations and conceptual clarifications related to material properties and processing methods.

Discussion Character

  • Technical explanation, Conceptual clarification, Debate/contested

Main Points Raised

  • One participant expresses confusion about negative signs in reduction calculations, questioning if they are normal.
  • Another participant suggests that negative signs indicate a reduction in size and recommends using positive values instead.
  • A participant confirms their use of the same bar for multiple rollings and seeks clarification on their equation for calculating reduction.
  • There is a discussion about producing graphs of Hardness versus Reduction, with one participant noting that the resulting graphs are neither linear nor curved, leading to difficulties in explanation.
  • Another participant observes a trend that as the reduction of area increases, hardness also increases.
  • A later reply requests further explanation on how cold rolling affects the hardness of metals.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the interpretation of negative signs in calculations. While some suggest using positive values, the initial confusion remains unresolved. The relationship between reduction and hardness appears to have some agreement on a general trend, but detailed explanations are still sought.

Contextual Notes

Participants reference specific calculations and data points without providing complete context for assumptions or definitions used in their equations. The relationship between cold rolling and hardness is discussed, but the underlying mechanisms and detailed explanations are not fully articulated.

Who May Find This Useful

This discussion may be useful for individuals interested in materials science, particularly those studying the effects of mechanical processing on material properties, as well as those involved in practical applications of cold rolling techniques.

mikex24
Messages
86
Reaction score
0
I have some difficulties on calculating the reduction on cold rolling process but mi signs is negative. Is that normal? Cheers
 
Last edited:
Physics news on Phys.org
Your negative sign just means that the bar is reducing in size. Just put the values as positive.

For the second reading, if you took the already reduced bar and reduced it again, then your 'original' readings would be from the first set.

BUT if you took a new bar, and then reduced it, it would be the actual original readings.
 
Thank you for the reply.. I use the same bar for all of the rollings. So my second equation to calculate the reduction will be like this one? ((5.25-5.83)/5.83)/100 ??
 
mikex24 said:
Thank you for the reply.. I use the same bar for all of the rollings. So my second equation to calculate the reduction will be like this one? ((5.25-5.83)/5.83)/100 ??

That should be it, yes.
 
Thank you very much for the help.
 
I am trying to produce the graphs of the Hardness VS Reduction which i calculated and then to explain the effect of cold rolling on Hardness. I produce those graphs but seems something is wrong. The graphs which produced it is not linear and no curve and i can't make any explanation... Any help? Cheers

For example:
Hardness:
65.3
45.3
84.7
89.2
93.2

Reduction:
0
9.33
18.35
29.7
42.14
 
Last edited:
It looks like on average, as your reduction of area increases, so does the hardness.
 
Thanks :).. Can you explain me little more the effect of cold rolling on hardness of the metals ? How does cold rolling effect on the hardness of the materials...? Cheers
 
Last edited:

Similar threads

Length of a plate after roll forging?
  • · Replies 6 ·
Replies
6
Views
2K
Can you explain this video? (An I-beam cut in half, springs apart, curved)
  • · Replies 5 ·
Replies
5
Views
4K
Q3.10: Power Calculation w/ Reduction Gear
  • · Replies 6 ·
Replies
6
Views
2K
What is the warmest and thickest sweater I can wear in a cold theater?
  • · Replies 8 ·
Replies
8
Views
2K
Finding the time for an object to start rolling without slipping
  • · Replies 4 ·
Replies
4
Views
2K
Undergrad Centrifugal separation into hot & cold air streams?
  • · Replies 1 ·
Replies
1
Views
2K
Undergrad What are the possible states of cold iron balls?
  • · Replies 2 ·
Replies
2
Views
2K
MHB Staff reduction rate from annualized to monthly rates
  • · Replies 1 ·
Replies
1
Views
1K
Dice Rolling probability (matlab)
  • · Replies 1 ·
Replies
1
Views
7K
How Do You Handle the Negative Gain When Calculating Resistance?
  • · Replies 4 ·
Replies
4
Views
2K