Active Corrosion Monitoring Successful Case Studies-CMPND

2012 MISTRAS GROUP, INC. ALL RIGHTS RESERVED. DISSEMINATION, UNAUTHORIZED USE AND/OR DUPLICATION NOT PERMITTED.

ACTIVE CORROSION MONITORING SUCCESSFUL CASE STUDIES

Miguel A. Gonzlez Nez Ph. D; Alain Proust Ph. D; Jean-Claude Lenain Ph. D; Valery Godinez Ph. D


Acoustic Emission Basic Process and Definition

Words from

the Definition: . . . transient . . . elastic . . . waves . . . rapid . . . localized . . . source


Scale of AE Source Processes

AE Source Amplitude will be Governed by (a) Size, (b) Speed of Source Event


Corrosion of Steel Plate

Steel plates with thick oxide film generate very strong AE signals with amplitudes over 80 dB during the corrosion process in a NaCl solution. It was also found that the signals with lower frequencies (20 80 kHz) are dominantly produced during the process.


Mechanism of SCC

=> Plastic blunting at crack tip

Step 1

Step 2

Step 3

Film formation

Brittle fracture

Environment

Film induced cleavage model


Pitting and crevice

Dislocation at pit tip

Spalling of corrosion products

? ?


Pitting and crevice

Salt crystal formation

H2 H+

H+ Hydrogen evolution


Corrosion of Steel Plate

The amount of current applied was calculated from a polarization curve on a similar material to make sure that corrosion was developed.


9

Overview: Localized Corrosion Catastrophic ruptures of industrial

plants Long initiation time but high

propagation velocity Inspection frequency not adapted

to prevent in service failures Environment industrial and human

incidence $1.7 Billion corrosion costs

Chemical and Petrochemical Industry

Cost : 4% Turnover chemical industry (30% due to SCC)

Pitt


PRELIMINARY INFORMATION

Correlation between actual cracks position along the sample located events

1985 original idea according to fractographic examination Stress Corrosion Crack (SCC) propagation => AE


Functions Selection Start a test Replay a test Data File transfer Delete File

Logistic Information Calibration Check out of the test feasibility (background noise level) Threshold Adjustment Data Acquisition (1 hour) Data stored on disk, report with graphs available ready for printing Calibration

1

2

3

4

5

6

7

8

ACTIVE CORROSION TEST DESCRIPTION, EASY TO USE


Yes Propagation of localized corrosion No

Corrosion rate correlated with AE activity Data base for corrosion rate on specific asset No quantification corrosion damage

Use of traditional AE with external loading (pressure, thermal stress) IPAC/MONPAC or NDT

Diagnosis


Acoustic Emission for anti-corrosion

Material has been chosen to resist to localised corrosion ! Corrosion could be a results of Process changes AE is NOT only a corrosion detection technique It is also a technique for expertise and for developing SOLUTIONS against corrosion Corrosion can be stopped or at least reduced if we know more about it

STRATEGY


14

Applications Insulated distillation column

Pipe supports Storage tanks Corrosion under insulation

(High/low temperature) Rail road Tank Car Al-Honeycomb Composites Enamel coated reactors Aerospace Industry: corrosion

protection characterization Detection of active corrosion

on grouted tendons on bridges


Early detection on high risk installation Case N1

MATERIAL : Duplex stainless steel Medium Cl- at 80C

Early detection of SCC crack propagation with CORPAC => Pipe changed before leak SCC Cracks

Some cracks have been detected in one plant => CORPAC exam has been done on the other plant using similar process


Risk based decision and corrosion monitoring SCC and Pitting, Case N 2

2 flat bottom storage tanks of 30 m3

Material : stainless steel (316Ti/19-25 HMo ST9)

In service temperature 90-100C

Organic Product


Action: Cleaning the product and maintain water


1996 CORPAC Very few AE Conclusion : No propagating corrosion

1997 CORPAC Strong AE localized at liquid/gas interface

Process analysis : 1 month before a dryer reactor had failed water in the product

1998-2001 CORPAC Small rate of AE Conclusion : Reduced corrosion rate

Risk based decision and corrosion monitoring SCC and Pitting, Case N 2


Question : How extent was the damaged area ?

Insulated distillation column (18m high)

In service temperature 150C

Material stainless steel (316 Ti)

Stress corrosion detected by dye penetrant

Damaged area characterization : SCC Case N3


AE activity restricted within a 2m high zone (cone)

confirmed partially with pulsed Eddy Current (only 4m were

inspected)

In Service AE Monitoring with CORPAC unit

Action : Partial repair with duplex stainless steel (2205)

Still in operation with any problems or leaks

Damaged area characterization : SCC Case N3


Repair not Validated Case 4 Piping System Material : Inconel 600 Temperature : 100C

Diagnosis : ACTIVE localized corrosion Detected damage : SCC cracks Every repair increase the crack speed


Heat Insulated Piping System Stainless steel 304L 1993 Leaks due to SCC cracks PT inspection => partially repaired in 1997 Paint + aluminum sheet + hydrophobic insulation + waterproof metallic shell Question : efficiency of anti corrosion protection?


Use of Acoustic Emission to detect localised corrosion under passive

protection, illustrated with industrial examples


Laboratory experiments: technical validation

10x 15 cm sample E24 low carbon steel plate

Protected with 400m of epoxy coating.

Before aging

One hour of AE monitoring in salt water : NO AE

AE TEST # 1



2 AE measurements of 6 samples

Aging 2 months of immersion in salt water + 2 months

saline mist + UV light

AE TEST # 2 AE TEST # 3


0

200

400

600

800

1000

1200

1 2 3 4 5 6


Aging 2 months of immersion in salt water

+ 2 months saline mist + UV light

AE activity VS sample number

+


Case history N9: Internal Coating Characterization Rail road tankcar (out of service) Corrosion protection ebonite

Artificial defects

on internal ebonite coating

3 drilled holes

(2, 5, 10 mm diameter)

Filled with industrial water

Rhoditech

2012 MISTRAS GROUP, INC. ALL RIGHTS RESERVED. DISSEMINATION, UNAUTHORIZED USE AND/OR DUPLICATION NOT PERMITTED. Rhoditech

Artificial defects

outlet

Top side near man

way

Case history N9: Internal Coating Characterization


Results :

AE from an artificial defect of ebonite coating AE from the top side near man way: in service defect AE from bottom side outlet: in service defect

Coating is degraded (change of color but not detectable with electrical measurements)

Addition of 60 liters of chloride acid strong increase of AE activity up to 1 event/sec

Rhoditech

Case history N9: Internal Coating Characterization


Annular Ring on Storage Tanks


AE Expert System

Early detection on high risk installation (without shutdown) Zonal location of damaged area Corrosion monitoring identification of transient stage which promotes localized corrosion characterization of corrosion rate

Validation of repair or corrosion protection Help for in situ material choice

Diagnosis


Non Intrusive Real Time Corrosion Monitoring

CORPAC TECHNOLOGY a) Find areas of active local

corrosion in pipes or vessels 1m (3ft) radius from AE sensor

b) Specific Areas (Welds, narrow geometries)

c) Large Areas can be tested with a multichannel system

d) Identify process stage or tweak process parameters to eliminate active corrosion


Thank you for your interest

Contact us at (609) 716-4080

E-mail: [email protected] www.mistrasgroup.com

Active Corrosion Monitoring Successful Case StudiesAcoustic Emission Basic Process and DefinitionScale of AE Source ProcessesCorrosion of Steel PlateMechanism of SCCPitting and crevicePitting and creviceCorrosion of Steel PlateOverview: Localized CorrosionPRELIMINARY INFORMATIONNmero de diapositiva 11Nmero de diapositiva 12Nmero de diapositiva 13ApplicationsEarly detection on high risk installationCase N1Nmero de diapositiva 16Nmero de diapositiva 17Nmero de diapositiva 18Nmero de diapositiva 19Nmero de diapositiva 20Repair not Validated Case 4Heat Insulated Piping SystemNmero de diapositiva 23Nmero de diapositiva 24Nmero de diapositiva 25Nmero de diapositiva 26Nmero de diapositiva 27Nmero de diapositiva 28Nmero de diapositiva 29Annular Ring on Storage TanksAE Expert SystemNon Intrusive Real Time Corrosion MonitoringNmero de diapositiva 33

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Active Corrosion Monitoring Successful Case Studies-CMPND