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Determining Conformance to Steel Profile/Surface Roughness/ Determining Conformance to Steel Profile/Surface Roughness/

Determining Conformance to Steel Profile/Surface Roughness/ - PowerPoint Presentation

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Determining Conformance to Steel Profile/Surface Roughness/ - PPT Presentation

William D Corbett KTATator Inc Webinar Content Review of industry standards Review of instrumentation and measurement acquisition procedures Content of Proposed SSPC Standard Learning ObjectivesOutcomes ID: 243702

profile surface astm measurement surface profile measurement astm roughness peak blast amp steel location mils process method appendix count

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Slide1

Determining Conformance to Steel Profile/Surface Roughness/ Peak Count Requirements

William D. CorbettKTA-Tator, Inc.Slide2

Webinar Content

Review of industry standardsReview of instrumentation and measurement acquisition procedures

Content of Proposed SSPC StandardSlide3

Learning Objectives/Outcomes

Completion of this webinar will enable the participant to describe:

The industry standards for surface profile, surface roughness and peak count measurement

The instruments used to measure surface profile/ roughness and to quantify peak count

The proposed content of the SSPC standard,

“Procedure for Determining Conformance to Steel Profile/Surface Roughness/Peak Count Requirements”Slide4

Industry Standards for Surface Profile, Surface Roughness and Peak Count Measurement

ASME B46.1, Surface Texture (Surface Roughness, Waviness and Lay)ASTM D4417, Standard Test Methods for Measurement of Surface Profile of Blast Cleaned Steel

ASTM D7127, Standard Test Methods for Measurement of Surface Roughness of Abrasive Blast Cleaned Metal Surfaces Using a Portable Stylus InstrumentSlide5

Industry Standards for Surface Profile, Surface Roughness and Peak Count Measurement, continued

ISO 4287, Geometrical Product Specifications (GPS) - Surface Texture: Profile Method - Terms, Definitions and Surface Texture ParametersISO 8503, Preparation of steel substrates before application of paints and related products - Surface roughness characteristics of blast-cleaned steel substrates

Part 4: Method for the calibration of ISO surface profile comparators and for the determination of surface profile - Stylus instrument procedure

Part 5: Replica tape method for determination of the surface profile

NACE SP0287, Field Measurement of Surface Profile of Abrasive Blast Cleaned Steel SurfacesSlide6

Proposed

SSPC Standard

Procedure for Determining Conformance to Steel Profile/Surface Roughness/Peak Count Requirements

Draft #6b (May 21, 2012) in SSPC Standards Review Committee (SRC)

After SRC approval, SSPC Board must approve

Timeline for approval is unknown at this timeSlide7

Content of

Proposed SSPC Standard

Scope; Description; Referenced Standards; Definitions

Description of Instruments; Verification of Accuracy

Required Number & Location of Readings

Reporting

Conformance to the Specified Surface Profile Range

Appendix A: Calibration & Verification of Accuracy

Appendix B: Determining Compliance based on Process Control Procedure

Appendix C: Additional Considerations when Measuring Surface ProfileSlide8

Instrumentation and Measurement Acquisition Procedures

Visual ComparatorsDepth MicrometersReplica Tape

Stylus InstrumentsSlide9

Visual Comparators

ASTM D4417, Method A5-10 X illuminated magnifier

Comparator Disc

Slide10

Visual Comparators

Three Comparator DiscsS: Sand

G/S: Grit/Slag

SH: Shot

Stencil Code

Profile depth (

2

)

Abrasive Type (

S

and)

Year reference (19

70

)Slide11

Visual Comparators

Select DiscAttach Disc to Comparator

Examine Surface

Select Segment(s)Slide12

ISO Visual Comparators

Grit or Shot prepared surfaces

Used with 5-10X magnifierSurface roughness “graded” as:

Fine

Medium

CoarseSlide13

Depth Micrometers

Instrument sets on peaks of the profile while a conical-shaped point projects into the valleys

Digital models store and upload data for analysis (“paperless”)Slide14

Replica Tape

Used in conjunction with a spring-loaded micrometer (analog or digital)

Compressible foam attached to 2 mils of polyester film (Mylar®

)

Digital version of micrometer can upload data (USB)Slide15

Replica TapeSlide16

Using HT Replica Tape

Obtain measurement with X-Coarse replica tape

If reading is 0.8-1.5 mils (red zone), record the measurement using Coarse tape

If reading is 2.6-4.5 mils (blue zone), record the measurement using X-Coarse tape

If reading is between 1.5-2.5 mils using X-Coarse, obtain a second reading (same location) with the Coarse tape

If the reading with the Coarse tape is also within 1.5-2.5 mils inclusive, average the two valuesSlide17

Portable Stylus Instruments

(ASTM D7127)

Retractable arm with diamond point stylus

Arm is automatically retracted

Rt

:

The distance between the highest peak and the lowest valley within any given evaluation length

Rmax

:

The greatest distance between the highest peak and lowest valley for any of the five sampling lengths that comprise an evaluation length

Pc:

The number of peak/valley pairs, per unit of evaluation length, extending outside a “

deadband

” centered around the mean line over the sampling lengthSlide18

Frequency of Surface Profile Measurements

No. of readings indicated in ASTM standards

No. of locations

not

indicated in ASTM standardsNo. of

locations

may be indicated by the project specification

Proposed SSPC Standard provides no. of

locations

to characterize the surface

Primary purpose of this webinarSlide19

Number of Readings (to determine

location average)

Based on Test Method (unless otherwise specified)ASTM D4417

“Sufficient” number of readings for Method A (visual comparator)

10 readings per “location” for Method B (depth micrometer)

3 readings per “location” for Method C (replica tape)

ASTM D7127 (portable stylus instrument)

5 traces per “location”Slide20

Number of Locations (to characterize the surface)

Minimum of three 6” x 6” (15cm x 15cm) locations

Per surface preparation “apparatus”Per work shift or 12-hour period (whichever is shorter)

Optional method (Non-mandatory Appendix B)

Based on changes in process between acceptance of jobsite standard & completion of production surface preparationSlide21

Surface Preparation “Apparatus”

Individual Blast Pot (multiple nozzles) [1]

Individual abrasive recycling/blast cleaning units (multiple pots) [2]

Individual centrifugal units (stationary or mobile)

[3]

Individual power tool

[4]

1

2

3

4Slide22

Reporting

Report:Range of Location Averages (lowest location average & highest location average)

Surface Profile Measurement (per “apparatus”)

Example (based on replica tape):

Location 1: 4.5, 4.8, 4.1 mils; (4.5)

Location 2: 4.0, 5.0, 3.8 mils; (4.3)

Location 3: 3.5, 4.1, 4.8 mils; (4.1)

Range: 4.1-4.5 mils; Average 4.3 milsSlide23

Conformance to the Specified Surface Profile Range

The average of the “location averages” must fall within the specified surface profile rangeLocation averages and average surface profile measurements outside of the specified range are not acceptable

The magnitude of the non-conforming surface profile measurement areas must be determined, marked and recordedSlide24

Non-conforming Location

OK

OK

OK

OK

Non-conforming Location

OK

OK

OK

End of Prepared Area

6” x 6” (15cm x 15cm) areas

Chalk line demarcating non-conforming areaSlide25

Appendix A:

Calibration & Verification of Accuracy (shop/field)

Calibration of instruments (applies to ASTM D4417 methods B&C; ASTM D7127)Calibration by manufacturer or approved laboratory only

Recalibration per manufacturer’s recommended interval (typically annual)

Obtain a dated Certificate of Traceability Slide26

Appendix A:

Calibration & Verification of Accuracy (shop/field)

ASTM D4417

Method A (visual comparator): visual for damage

Microscopic examination in a laboratory to confirm depth of valley relative to corresponding peak (if necessary)Slide27

Appendix A:

Calibration & Verification of Accuracy (shop/field)

ASTM D4417

Method B (depth micrometer)

Zero set (float glass plate) beginning & end of shift

Verify accuracy using shim with cut-out/hole on float glass plate

Verify cone tip condition using 10x magnifier

Tips are replaceable (re-verify accuracy upon replacement)Slide28

Appendix A:

Calibration & Verification of Accuracy (shop/field)

ASTM D4417

Method C (replica tape)

Select appropriate tape

Coarse (0.8-2.5 mils)

X-Coarse (1.5-4.5 mils)

X-Coarse Plus (4-5 mils)

Recheck if in “overlap area” of 1.5-2.5 mils

Verify accuracy of micrometer using traceable shimsSlide29

Appendix A:

Calibration & Verification of Accuracy (shop/field)

ASTM D7127 (portable stylus instrument)

Set gage parameters (sampling & evaluation length,

deadband

& filter) per Standard

Verify accuracy using standard (provided with gage) prior to each useSlide30

Appendix B: Determining Compliance Based on Process Control Procedure

Based on establishing a process control prior to production blast or power tool cleaningWithin 15 minutes after start of surface preparation, prepare sample area (min 2’ x 2’)

Measure surface profile. If surface profile conforms, document process control itemsSlide31

Appendix B: Determining Compliance Based on Process Control Procedure

A change in process during production requires re-measurementDenote time of the change & location of surfaces prepared prior to the change

Obtain two measurements at random locations

One in an area prepared prior to the change in process

One in an area prepared after the change in process

Document: Locations of tests; test method(s); test results; conformance to specification

The magnitude of the non-conforming surface profile measurement areas must be determined, marked and recorded (as described earlier)Slide32

1

Worker performing abrasive blast cleaning

2

Blast nozzle type

3

Blast nozzle size

4

Number of nozzles operating from same compressor

5

Abrasive manufacturer

6

Abrasive type, hardness and physical shape (e.g., steel grit, steel shot, or ratio of mix, or type of mineral abrasive, such as garnet, coal slag, etc.)

7

Abrasive size (sieve size)

8

Air pressure at nozzle

9

Blast hose length (as a range)

10

Blast hose diameter

11

Compressor size (CFM)

12

Air pressure at compressor

TABLE B1

PROCESS CONTROL ITEMS

FOR ABRASIVE NOZZLE BLAST CLEANING Slide33

1

Worker performing power tool cleaning

2

Power tool type, model and manufacturer

3

Power tool media manufacturer

4

Type of media used (e.g. wire brush, coated abrasive disc, abrasive embedded in

matrix,

wire

bristle,

impact tool)

5

Abrasive media size

6

Grade of media

7

Replacement/substitution of consumables (e.g., disc, wire brush, needles, bristles)

8

Compressor size (CFM) if tool is air-powered

TABLE B2

PROCESS CONTROL ITEMS

FOR POWER TOOL CLEANING (SP 11, SP 15 only)Slide34

1

Unit Operator

2

Blast wheel type

3

Wheel motor power

4

Wheel positioning

5

Control cage movement

6

Media flow rate

7

Abrasive manufacturer

8

Abrasive type and physical shape (e.g., steel grit, steel shot, or ratio of mix, or type of mineral abrasive, such as garnet, coal slag, etc.)

9

Abrasive size (sieve size)

10

Configuration, orientation and size of piece being cleaned (if in shop)

TABLE B3

PROCESS CONTROL ITEMS

FOR CENTRIFUGAL BLAST CLEANINGSlide35

Appendix C: Additional Considerations

Measuring surfaces prepared in the shop using centrifugal blast cleaning unitsPotential for variability due to wheel alignment and configuration of item

Measuring surfaces prepared using portable centrifugal blast cleaning units

Potential for variability due to uneven distribution of blast mediaSlide36

Appendix C: Additional Considerations

Measuring surface profile exposed by waterjetting

unitsProfile may vary considerably. Additional measurement locations may be required

Measuring surfaces prepared using power tools (SSPC-SP11; SP15)

Consider productive life of cleaning media; Additional measurement locations may be required

Use ASTM D4417, Method B

onlySlide37

Appendix C: Precautions

Determining surface profile on flame cut edgesRemoval of carburization (hardening) may be required prior to blast cleaning

Effect of existing surface profile on newly generated surface profileExisting profile beneath coating may exceed specified profile for maintenance painting. Prepare test area prior to production work

Pitted steel: Measure in non-pitted areasSlide38

Summary

During this webinar, we have described :The industry standards for surface profile, surface roughness and peak count measurement

The instruments used to measure surface profile/ roughness and to quantify peak count

The proposed content of the SSPC standard,

“Procedure for Determining Conformance to Steel Profile/Surface Roughness/Peak Count Requirements”Slide39

Determining Conformance to Steel Profile/Surface Roughness/ Peak Count Requirements

William D. CorbettKTA-Tator, Inc.

THE END