# Homework Help: Corrosion Rate

1. Oct 23, 2007

### Wiccan_Childe

Hi, I have a problem, and I'm not looking for anyone to give me the answers, just a pointer in the right direction would be fantastic.

eg. Iron
Material Density (g/cm^3) = 7.87
Oxidation State (Z) = 2
Corrosion Current Density (amps/cm^2) = 2.5*10^4
Atomic Weight (g/m) = 55.8
Corrosion Rate = ??

We're given a list of equations, as follows -
Rate= j/nF
density = m/v
o= Ee
F = 96,500 Coul/mol
o= F/Ao
1 MPa = 10^6 N/m^2

I have no idea which equations to use even, I'm very new to physics, and would appreciate anyone who can help me out, because I want to be able to solve (and understand!!) how to figure it out.

Thankyou!

2. Oct 23, 2007

What are you finding the corrosion rate of? You didn't describe the problem at all.

3. Oct 23, 2007

### Wiccan_Childe

All we're given is the info below in a table, and this paragraph before it...

Deterioration or corrosion of a prosthetic device is an important factor for the selection of a material. For a metal to retain its mechanical properties over the lifetime of the implant the corrosion rate must be less than 2.50 x 10-4 mm/yr. In the following table calculate the corrosion rate in mm/yr for each of the materials.

4. Oct 23, 2007