Hi Question related to Gears and their chemical composition

[MustafaRauf]

Hi ! This is Mustafa. I recently did my bachelor's and started working with Honda Motors.

So my manager asked me to do a little research regarding the Gear type (SCM415H) used. I have to check how varying the chemical composition of each element will result in the properties of the gear itself. Here is the list of elements and the standard compositions:

C (0.12-0.18%)
Si (0.15-0.35%)
Mn (0.55-0.90%)
P (0.03 max)
S (0.03 max)
Cr (0.85-1.25%)
Mo (0.15-0.30%)

I am not great with chemistry (since I am a design&simulation engineer) and can't find a lot of help on the internet. I need to know the specifics, how reducing and increasing the levels of each element will change the properties of the gear.

Thanks

 

[jedishrfu]

Welcome to PF!

What you are interested in is not really Chemistry but Materials science.

Here's a reference to some of its concepts and toward the end are some plots of for how some steels respond based on carbon content...

http://people.virginia.edu/~lz2n/mse209/Chapter6.pdf

For gears, shearing is an important concept. I once assisted a machinist who maintained the college clock. Every winter it would freeze up and so to prevent major repairs he used a brass gear at a key spot that would shear and relieve the stress to the rest of the mechanism. He chose brass over steel because the brass sheared at a lower amount of force applied by the clock motor.

 

[MustafaRauf]

Welcome to PF!

What you are interested in is not really Chemistry but Materials science.

Here's a reference to some of its concepts and toward the end are some plots of for how some steels respond based on carbon content...

http://people.virginia.edu/~lz2n/mse209/Chapter6.pdf

For gears, shearing is an important concept. I once assisted a machinist who maintained the college clock. Every winter it would freeze up and so to prevent major repairs he used a brass gear at a key spot that would shear and relieve the stress to the rest of the mechanism. He chose brass over steel because the brass sheared at a lower amount of force applied by the clock motor.

Thankyou Jedi

I did go through the file and it mostly covers the properties. It however does not let me know how varying their compositions will effect the material (in this case a gear)

I did find some info but was hoping for a little specif answer.

Here:

Manganese: Used for increasing the hardness and strength of a gear. However it decreases ductility and weldability and effects the hardenability of steel.

I am looking for something like this about the elements mentioned above that are added in the manufacturing of a transmission gear.

 

[jedishrfu]

I found a website dedicated to gear technology that may have more specific articles. In particular, I searched on metallurgy and got the following hit:

http://www.geartechnology.com/issues/0396x/howes.pdf

There are other articles as well so checkout the site www.geartechnology.com

 

[MustafaRauf]

Thanks. I've managed to find I what I was looking for. Where can I find the microstructure details on the Jis steel scm415h?