Suez University

Faculty of Petroleum and Mining Engineering

Metallurgical Department

Corrosion rate
experimental
Report
Prepared by:
1. Abdulrahman emad Hussain Sec:- 2.
2. Aya Mohamed mostafa Sec:- 1.
3. Aya Samir Hussain Sec:- 1.
4. Nihal ahmed Mahmoud Sec:- 3.
5. Hanaa Mohamed Ibrahim Sec:- 3.
6. Aya desouky hozayen Sec:- 1.
7. Marwa hamada hagag Sec:- 3.
8. Radwa Mohamed Sec:- 2.

Content:
 1. Introduction
2. Objectives
3. Tools
4. Procedures
5. Calculations
6. Results
7. References

 Introduction:
Corrosion rate is the speed at which any metal in a
specific environment deteriorates. It also can be defined as the
amount of corrosion loss per year in thickness. The speed or
rate of deterioration depends on the environmental conditions
and the type and condition of the metal under reference. The
corrosion rate can be expressed by one of the following:
1.gram or milligram
2.gram/cm2/day or milligram/dm2/day
3.Inch/year or millimeter/year
4.mil/year (where mil=1x10-3 inch)
We are going to determine the corrosion rate for four different
steel specimens with cylindrical shape and different diameters
and heights; with three units:

∆w
1. CR(mmd) = At
 ∆w is loss in weight in milligram
A is area exposed to corrosion in dm2
t is the time in day.

∆w
2. CR(g/sec) = t

∆w is loss in weight in gram

t is the time in second.

∆w
3. CPR(mm/yr)= 87.6 ×
DAt ,

∆w is loss in weight in milligram

D is density = 7.68 g/cm2
t is the time in hr
A is area exposed to corrosion in cm2

 Objectives:
1. Determine the corrosion rate for steel in many different
environments.
2. Calculate the corrosion rate using different units.

 Tools:
1. Four steel specimens with different dimentions.
2. Four different solution used as environments
(10% H2SO4 and 20% H2SO4 and 10% HNO3 and 20% HNO3).
3. Weighing scale.
4. Micrometer.
5. Timer.

 Procedures:
1. Weight the four specimens and measure the dimentions.
2. Prepare the four solutions (10% H2SO4 and 20% H2SO4 and
10% HNO3 and 20% HNO3)
3. Put each specimen in its prepared solution.
4. Wait for period of time to let the corrosion takes place.
5. Remove the specimens from the solutions.
6. Weight the specimens after corrosion.
7. Calculate the CPR(mm/yr), CR(g/sec) and CR(mmd).

 Calculations:
No.1 No.2 No.3 No.4
Wt.1(gm) 6.2298 7.662 14.0108 12.1164
10% 20%
Sol. 10% HNO3 20% HNO3
H2SO4 H2SO4
Length2.(mm) 18.8 10.58 15.56 14.4
Width2
15.37 11.03 13.35 11.83
”Diameter2”.(mm)
Thickness2.(mm) 2.71 ----- 8.87 8.77
Area(mm2) 783.07 557.72 1.8425×103 1.494×103
Wt.2(gm) 6.2211 7.5935 13.9824 11.99

A. For (10% H2SO4):

 3
∆ w (6.2298−6.2211)×10
1. CR(mmd) = A t = 783.07 ×10−4 ×7 =15.872mmd

∆ w 6.2298−6.2211 −8 g
2. CR(g/sec) = t
=
7 ×24 ×60 ×60
=1.4385 ×10
s

3. CPR(mm/yr)=
3
∆w (6.2298−6.2211)× 10
87.6 × =87.6 × −4
=86.109 ×10−3 mm / yr
DAt 7.68 × 783.07× 10 ×(7 × 24)

B. For (20% H2SO4):

3
∆ w (7.662−7.5935)× 10
A. CR(mmd) = At
= −4
557.72×10 ×7
=175.5 mmd

∆ w 7.662−7.5935
B. CR(g/sec) =
−7
= =1.1326 ×10 g/ s
t 7 × 24 ×60 × 60

3
∆w (7.662−7.5935)× 10
C. CPR(mm/yr)= 87.6 ×
DAt
=87.6 × −4
7.68 × 557.72×10 ׿ ¿

C. For (10% HNO3):

3
∆ w (14.0108−13.9824 )×10
A. CR(mmd)= A t = 1.8425 ×10 3 ×10−4 ×7 =22mmd

∆ w 14.0108−13.9824
B. CR(g/sec) =
−8
= =4.696 ×10 g /s
t 7× 24 × 60× 60
C. CPR(mm/yr)=
3
∆w (14.0108−13.9824 )× 10
87.6 × =87.6 × =119.465×10−3 mm / yr
DAt 7.68 × 1.8425× 103 × 10− 4 ×(7 × 24)

D. For (20% HNO3):

3
∆ w ( 12.1164−11.99 ) ×10
A. CR(mmd)= A t 1.494 ×10 3 ×10−4 ×7 =120.9 mmd
=

∆ w 12.1164−11.99
B. CR(g/sec) =
−7
= =2.0899 ×10 g /s
t 7 ×24 × 60 ×60

3
∆w (12.1164−11.99)×10
C. CPR(mm/yr)= 87.6 ×
DAt
=87.6 ×
7.68 × 1.494 ×103 ×10−4 ׿ ¿

mdd
200

180

160

140

120
mdd
100

80

60

40

20

0
10% H2SO4 20% H2SO4 10% HNO3 20% HNO3
  Results:
1. The solution H2SO4 has the highest corrosion rates.
2. By increasing the concentration of the solutions the
corrosion rates increase.
3. By increasing the time the corrosion is increased.
4. CPR(mm/yr) is the best to represent the corrosion rate as it
shows the penetration of the corrosion.