industry quality review september 2008 nace central area conference

Industry Quality ReviewSeptember 2008

NACE Central Area Conference

Magnesium AnodeElectrochemical Properties

-1.75V Open Circuit Voltage High Potential

-1.55V Open Circuit Voltage Standard Alloy

1000 Amp-hrs/pound - Theoretical

500 Amp-hrs/pound - Nominal

50% current efficiency - Nominal

Quality & Performance Factors

Alloy Chemistry

Potential (voltage)

Current efficiency

Alloy Chemistry

ASTM B843 defines alloy requirements

>98.5% magnesium

Typically, 100% testing of every heat

Chemistry alone does not identify quality

Open Circuit Potential

Hi-potential magnesium -1.75V to -1.77V

Standard alloy -1.50V to -1.55V

Open circuit potential is controlled by chemistry and casting process

Current Efficiency

% of energy within the alloy that is available as cathodic protection current

Measured in Amp-Hr/pound

Nominal 50% efficiency for both H-1 and high potential alloys

Determines life of anode

ASTM G97 test (Destructive test, 14 days, $1000 cost

Anode Life

Life (yrs) = 0.116 x Wt (lbs) x Efficiency x 0.85 (Utiliz. Factor)

Anode Current (amperes)

Value Analysis*Efficiency Life (Years) Annual Cost

50% 16.76 $14.92

40% 13.41 $18.64

30% 10.05 $24.87

20% 6.70 $37.31

*17# anode at 50 mA, Assumes total installed cost of $250

Alloy and market development by DowForeign sources (China, Russia, Mexico) entered

market in late 90’sInitial quality problems with foreign anodes Foreign quality problems resolved by 1999US suppliers not competitive with foreign sourcesChina/Mexico dominant suppliers to US market by

2002

Mag Anode Industry History

Quality Developmentof Foreign Sources

Early 98

Late 98

1999

60

56

52

48

44

40

36

32

28

1.65 1.70 1.75 1.80 1.85OPEN CIRCUIT POTENTIAL IN (-) VOLTS (vs CuCuSO4)

2002/ 2003Quality Results

60

56

52

48

44

40

36

32

28

%C

UR

RE

NT

EF

FIC

IEN

CY

1.65 1.70 1.75 1.80 1.85OPEN CIRCUIT POTENTIAL IN (-) VOLTS (vs CuCuSO4)

2003 Industry Sampling

5 high potential anodes obtained on open market in mid-2003

Tested according to ASTM G97 standard by third-party laboratory

Results confirmed widespread quality problems in industry

2003 Industry Sample Results

A -1.75v 49.3% 16.53 $15.12

B -1.72v 41.6% 13.95 $13.98

C -1.63v 12.1% 4.06 $61.58

D -1.63V 11.0% 3.69 $67.75

E -1.61v 4.8% 1.61 $155.28

Sample OCP vs Current Life* Annual CuCuSO4 Efficiency (yrs)

Cost**

*17# anode at 50 mA, **Assumes total installed cost of $250

Quality Concern Validation

Anode quality presentation by T. May (MESA) in Oct 2003 w/publication in MP in Jan 2004

Anode quality presentation by B. Gummow (CORRENG) in Feb 2004 at Northern Area Conference

Anode quality presentation by M. Yunovich (CCTechnologies) in Mar 2004 at Corrosion 2004

Quality concerns apparent in late 2002/2003Producers capable, but not providing qualityDiminished user quality control programsImpact of low quality magnesium not well

understood

2003 Industry Assessment

2005 Industry Sample Results

A -1.81 57% 19.11 $13.08

B -1.79 56% 18.77 $13.32

C -1.79 55% 18.44 $13.56

D -1.79 55% 18.44 $13.56

E -1.68 29% 9.72 $25.72

F -1.59 16% 5.36 $46.64

Sample OCP vs Current Life*Annual CuCuSO4 Efficiency (yrs) Cost**

*17# anode at 50 mA, **Assumes total installed cost of $250

2005 Industry Assessment

Quality of cast anodes is generally improvedExtruded magnesium anodes are quality alternativeNo significant changes in end-user QA programsStill some scrap out there

2007 Industry Sample Results

A -1.77 61% 20.45 12.22

B -1.77 55% 18.44 13.56

C -1.77 54% 18.1 13.81

D -1.75 46% 15.42 16.21

E -1.65 29% 9.72 25.72

F -1.60 26% 8.72 28.67

G -1.67 24% 8.05 31.06

H -1.60 10% 3.35 74.63

Sample OCP vs Current Life*Annual CuCuSO4 Efficiency (yrs) Cost**

*17# anode at 50 mA, **Assumes total installed cost of $250

2007 Industry AssessmentIndustry sampling validates continuing quality concernsNo significant changes in end-user QA programsRecent supply instability and price volatility likely to increase quality concerns

End-User Impact

Average of 2007

tests

-1.70V 38% 12.74 $19.62

Industry Standard

-1.75V 50% 16.76 $14.92

OCP vs Current Life* Annual

CuCuSO4 Efficiency (yrs) Cost**

*17# anode at 50 mA, **Assumes total installed cost of $250

+$4.70

ConclusionsAnode quality continues to be major industry concernEconomic impact to industry estimated at >$2MM per yearEnd-users and resellers largely unaware or unconcerned of impact of qualityInstability of magnesium market makes overall quality improvement unlikely

Industry Quality ReviewSeptember 2008

John Cole – MESA Products, Inc.