# Chapter 12 : Oxidation and Corrosion¶

## Example 12.1 Page No : 395¶

In [1]:

import math

# Variables
D = 320*10**-3;			#in meter
L = 1;			#in meter

# Calculation
A = math.pi*D*L;			#Surface area in meter**2
l = (200/A);

# Results
print 'the distance at which magnisium anode capable of giving 2MA = %.0f meters'%l

the distance at which magnisium anode capable of giving 2MA = 199 meters


## Example 12.2 Page No : 396¶

In [2]:

import math

# Variables
W = 0.0243;			#1 mole of magnesium weight(in Kg)
C = 2*96490;			#used charge (in A-s)
A = 15*10**(-3);			#current density (in A/metre2)
t = 10;			#time (in years)
T = 10*365*24*3600;			#time (in sec)

# Calculation
#amount of magnesium required  = charge required per m2 of hull surface for a design life of 10 years/(used charge for anode)
Mg_required = W*A*T/C;			#magnesium required per square meter of the hull surface for a design life of 10 years

# Results
print 'magnesium required per square meter of the hull surface for a design life of 10 years = %.1f Kg/m2'%Mg_required

magnesium required per square meter of the hull surface for a design life of 10 years = 0.6 Kg/m2