Suez University

Faculty of Petroleum and Mining Engineering

Metallurgical Department

Corrosion rate
experimental
Report
Prepared by:
1. Chaw1
2. Chaw2
3. Chaw3
4. Chaw4
SEC.
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 ,where ∆ 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 cylindrical steel specimens with different diameters and
heights.
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: ‫الصور هتتحط هنا‬
1. Weight the four specimens and measure the diameters and
heights.
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 1 hour 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)
Sol. 10% H2SO4 20% H2SO4 10% HNO3 20% HNO3
Ht.(mm)
Diam.(mm)
Area(mm2)
Wt.2(gm)

A. For (10% H2SO4):

−3
∆ w (w 1−w 2)×10
= =? mmd
1. CR(mmd) = At −4
A × 10 ×
1
24

∆ w w 1−w 2
2. CR(g/sec) =
−?
= =? ×10 g /s
t 60 ×60

−3
∆w (w 1−w 2)×10
3. CPR(mm/yr)= 87.6 ×
DAt
=87.6 × −2
7.68 × A × 10 ×1
−?
=¿ ? × 10 mm / yr

B. For (20% H2SO4):

 −3
∆ w (w 1−w 2)×10
= =? mmd
A. CR(mmd) = At −4
A × 10 ×
1
24

∆ w w 1−w 2
B. CR(g/sec) =
−?
= =? ×10 g /s
t 60 ×60

−3
∆w (w 1−w 2)×10
C. CPR(mm/yr)= 87.6 ×
DAt
=87.6 × −2
7.68 × A × 10 ×1
=¿ ? × 10−? mm / yr

C. For (10% HNO3):

−3
∆ w (w 1−w 2)×10
= =? mmd
A. CR(mmd) = At −4
A × 10 ×
1
24

∆ w w 1−w 2
B. CR(g/sec) =
−?
= =? ×10 g /s
t 60 ×60

−3
∆w (w 1−w 2)×10
C. CPR(mm/yr)= 87.6 ×
DAt
=87.6 × −2
7.68 × A × 10 ×1
=¿ ? × 10−? mm / yr

D. For (20% HNO3):

−3
∆ w (w 1−w 2)×10
= =? mmd
A. CR(mmd) = At −4
A × 10 ×
1
24

∆ w w 1−w 2
B. CR(g/sec) =
−?
= =? ×10 g /s
t 60 ×60

−3
∆w (w 1−w 2)×10
C. CPR(mm/yr)= 87.6 ×
DAt
=87.6 × −2
7.68 × A × 10 ×1
=?=? × 10−? mm / yr

 Results:
1. The solution HNO3 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.