Forging work ratio question 2

[metalguesser]

Friends!

I have a question (probably a dumb one) regarding Forging work ratio. We have a situation with a new product that we forge from a rectangular Continuous cast bloom 23.6" X 14.6" cut to 17.125" length. The forging was finished to size 17"X 18.125" X 17.125" in about 38 reduction steps. On calculating the work ratio I get a 48:1 work ratio, no matter how much I check and recheck. In our experience the max work ratio we come across is 20 and rarely 25. The question is; Are work ratios of this order common? Conversely is there actually that much work input or is there a different method of calculation if the reductions go beyond a certain limit? Appreciate any insight in to this.

Thanks and Regards

 

[CoryPad]

Is there a typo? Your initial cross-sectional area is 345 in², and your final is 308 in², which means the ratio is 1.12:1.

Regards,

Cory

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[metalguesser]

Corypad,

Thanks for the response. Yes there is a typo.
The forged finish is 17" X 18.125" X 17.75" Long.

I see that you are calculating the start and finish,
while I'm taking all intermediate stages in to consideration in my calculation. By intermediate stages I mean the multiple reductions (as mentioned 38 steps) that go in all the 3 directions. Probably that is where I could be going wrong.

Thanks in anticipation,

Regards

 

[metengr]

metalguesser;

From ASM Handbook Volume 14A, Glossary

reduction
(1) In cupping and deep drawing, a measure of the percentage of decrease from blank diameter to cup diameter, or of the diameter reduction in redrawing. (2) In forging, extrusion, rolling, and drawing, either the ratio of the original to the final cross-sectional area or the percentage of decrease in cross-sectional area.

 

[redpicker]

I think you may be making this too complicated.

When making multiple reductions, you multiply the reduction ratios of each step. However, I cannot imagine taking an initial 23.6" by 14.6" bloom and forging it to 17" X 18.125" and taking 38 steps. Maybe 3 steps, an initial upset, then a reduction of the 23.6" dimension to 18.125 and a final forging of the 17" dimension. This might get you to 3:1 reduction, but I'd doubt it.

rp

 

[arunmrao]

Forging work ratio

http://www.eng-tips.com/viewthread.cfm?qid=191256

Forging work ratio

http://www.eng-tips.com/viewthread.cfm?qid=191049

You might like to visit earlier threads on the same topic and the calculate the actual forging work ratio.

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