Hardness Test Procedure - PDF

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Doc. Ref. No.: SPSS/NDT/13 SPSS/NDT/13 Revision : 1 / 22 Oct. 2011 Page 1 of 8

H A R D N E S S T E S T P R O C ED ED U R E

Document No

:

SPSS/NDT/13

Revision No

:

1

Date Issued

:

22 OCT. 2011

Revision

Date

Revision Description

0

05 Sep. 2008

First Issue

1

22 Oct. 2011

Partial Revision

Issued by ________________ R. Mohamed Javidh ASNT NDT Level III (UT,MT,PT,RT&VT) File Number - 94493

Authorization __________________ Dr. Falah Abu Jarad General Manager


Doc. Ref. No.: SPSS/NDT/14 Revision : 1 / 22 Oct. 2011 Page 2 of 8

CONTENTS Ar ti cle No.

Ti tl e

Page No.

1.0

Scope

03

2.0

Referenced Codes / Standard

03

3.0

Definitions

03

4.0

Personnel Qualification

03

5.0

Personnel Responsibilities

03

6.0

Equipment

03

7.0

General Requirements & Procedure For Hardness Measurement

04

8.0

Acceptance Criteria

06

9.0

Testing Requirements

06

10.0

Attachment

07



1.0

Scope This procedure covers Hardness Testing method in determining the hardness of parent metal weldments and HAZ after PWHT is completed.

2.0

Reference Codes / Standards

3.0

4.0

2.1

ASME Sec. VIII Div. 1 (Edition:2010).

2.2

ASME B31.3 (Edition:2008).

2.3

NACE RP 0472 (Edition: 2000).

2.4

NACE MR0175 (Edition: 2000).

2.5

JERES W - 011

2.6

JERES A - 301

Definition

3.1

Brinell Hardness Test – an indentation hardness test using calibrated machines / equipment into the surface of the material under test and to measure the diameter of the impression after removal of the load.

3.2

Brinell Hardness number, HB – a number related to the applied load and to the surface area of the permanent impression made by a ball indenter.

3.3

Verification – Checking or testing to ensure conformance with the specification.

Personnel Qualification

4.1

5.0

Personnel Responsibilities

5.1

6.0

All personnel performing the Hardness Test should be knowledgeable about all aspects of operation of Hardness Test equipment and method.

The hardness testing inspector shall be responsible for,



Selection of equipment



Selection of proper test block



Surface preparation



Testing



Recording the test results and report preparation

Equipment

6.1 The equipment used for the purpose of measuring the Brinell Hardness number of the heat treated materials shall be limited to the following or the equivalent :



TELEWELD Portable Hardness Tester (TELEBRINELLER Hardness Tester). KRAUTKRAMER MICRODUR (MC-10) 6.2 Whenever the equipment is changed to other than mention in 6.1 this procedure shall be revised and approved for the same before start of job. 6.3 The calibration test block selected shall be of the same BHN as that expected in the material. For all practical purpose within the scope of this procedure the BHN value of test blocks selected shall be based on the maximum BHN permitted by the following table: -

MAXIMUM BRINELL HARDNESS

7.0

Material Group

Wet Sour, Amine, Caustic or Hydrogen Services

Other Service

P-1

200

200

P3, P4

225

235

P5, P6, P7

237

241

General Requirements & Procedure for Hardness Measurements

7.1

Hardness Inspection can be made on only two adjacent sides of the t est bars.

7.2

Replace the indenter (ball) when it is out-of-round.

7.3

All hardness impressions at one test location shall have at least 6.4mm between their edges or edge of the material.

7.4

Weld deposits shall be tested on the side contacted by the process liquid, whenever possible. If access to the process side is impractical, such as on piping or small – diameter vessels, testing shall be done as the opposite side.

7.5

Preparing The Test Surface : If necessary, use a grinder, sander or file to remove scale, rust and decarburized metal from the surface to be tested. On curved surfaces, grind a flat



spot large enough to contain the test impression. Care should be taken to avoid overheating or cold working the surface. The surface finish must be such that the edges of an impression are adequately defined when viewed through the Brinell microscope.



Care shall be taken to avoid excessive heating or cold working of the surface, which will change the hardness of the surface and lead to erroneous readings Do not take readings on scaled or discoloured areas.



Ensure that the test block is flat on the test surface.



7.6

Selecting the Telebrineller Test Bar: Maximum accuracy of Telebrineller tests is

maintained if the Brinell Hardness Number (BHN) of the Test Bar is no more than 10% harder or softer than the BHN of the tested part. The BHN of a Test Bar is etched on both ends. If the approximate BHN of the part is completely unknown, you may use any Test Bar to determine an approximate BHN. Then, if necessary, the accuracy may be refined by retesting with a Bar within the + or -10% range. 7.7

Inserting the Test Bar : Depress the Button on the Spacer Block Assembly (7) of the

Bar Holder and slide it forward to the end of the slot nearest the Anvil (2). Release the Button so it locks into the first detent. Insert a Test Bar (1) into the Bar Holder until it butts against the Spacer Block and proceed with making a test as described in the next three sections. After completing the first test, index. the Spacer Block Assembly back one notch and reinsert the Test Bar In the same orientation. Continue testing and indexing until 10 impressions have been made then return the Spacer Block Assembly to the front detent. Insert the opposite end of the Bar into the Bar Holder and repeat the process for 10 more tests. By following the same procedure for the other face of the Test Bar, max. 40 tests indentations can be made with each Bar. 7.8

Making the Impressions: Place the Bar Holder on the surface to be tested with the Anvil

(2) above the test location. If the Rubber Rear Piece (4) cannot rest on the same surface, it must be supported by hand so the Bar Holder remains parallel to the test surface. Using a hammer weighing at least 2 1/2 pounds, strike a sharp blow squarely on the Anvil. Pull the hammer back on the rebound so it does not bounce on the Anvil which can cause secondary impressions. To keep the blow square on the Anvil, so the Bar Holder does not move laterally and produce smeared impressions, grip the hammer handle close to the head and use a perpendicular punching motion rather than an arced swing. The force of the blow is not a critical factor but it 1s advisable that it be regulated to make impressions in the 3 mm to 4 mm range. On harder materials (above 450 BHN) smaller impressions will be satisfactory. 7.9

Measuring the Impressions: Place the Brinell Microscope over the impression in the test

specimen (6). If ambient light is insufficient, use the penlight on the scope to illuminate the impression. If necessary, screw the top lens up or down until, when looking through the scope, the measuring scale and the impression are both in sharp focus. Rotate the



upper part of the scope until the scale is crosswise to any surface striations and position the scope so the 1 mm graduation is over one edge of the impression.

Use

the scale at the

opposite side of the impression to measure the diameter. Note that the scale is graduated in .1 mm increments and measurements may be estimated to the nearest .05 mm. After recording the diameter of the impression in the test specimen, pull the Telebrineller Test Bar far enough from the Bar Holder to expose the corresponding impression and repeat the above process to determine its diameter. 7.10 Krautkramer Microdur 10 (MC-10) : Hardness tester utilizes a dynamic method based on energy measurements. Measured values of impact and rebound velocities are processed in a portable computer and digitally displayed as hardness in HB values. 7.11 Determining the Brinell Hardness : Having made and measured the impression in the test specimen and the Telebrineller Test Bar, the hardness of the specimen can be calculated as follows :

Alternatively, the hardness of the specimen can be found using the Telebrineller Computer (slide) which is part of the Teleweld Portable Telebrineller.

8.0

Acceptance Criteria

8.1 ASME B31.3 Table 331.1.1 lists hardness limits for production welds. Reading which exceed specified limits by 10BHN shall be cause for performing 3 additional tests local to the initial test area. The weld is considered acceptable if all three testes are below specified limits. If the readings remain out with that specified, the weld shall be considered unacceptable. 8.2 For H.I.C tested, hardness acceptance shall be as per NACE MR0175, Clause 3.2 (Carbon and Loy-Alloy Steel) and Clause 3.5 (Austenitic Stainless Steel) requirements

90

Test Requirements (Applicable only for Tests based on NACE RPO472)



9.1 Production Hardness Test shall be taken one every 3 meters of main seam weld, but not less than one set readings for each main seams. One test shall be taken on each nozzle, flange to neck, nozzle neck to shell, weld and piping butt weld. 9.2 Each welding procedure used shall be tested. 9.3 Testing of fillet weld deposits shall be done when feasible. One test shall be made for each 3 meter of weld length. 9.4 For piping welds, 5% minimum of the butt welds shall be tested, unless otherwise specified in the contract. 10.0

Attachment

10.1 Report Form for Hardness Test.


Report Form for HT


Hardness Test Procedure - PDF

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