NES 822 Part 2 Requirements for Nickel Chromium Molybdenum Niobium Allloy 625

Ministry of Defence Defence Standard 02-822 (NES 822)

Issue 1 Publication Date 01 April 2000

Incorporating NES 822 Category 2

Issue 2 Publication Date December 1993

Nickel Chromium MolybdenumNiobium Alloy 625

Part 2Sand Castings And Ingots

DStan

DStan is now the publishing authority for all Maritime Standards (formerly NESs). Any reference to any other publishing authority throughout this standard should be ignored. Any queries regarding this or any other Defence Standard should be referred to the DStan Helpdesk as detailed at the back of this document.

AMENDMENT RECORD

Amd No Date Text Affected Signature and Date

REVISION NOTE

This standard is raised to Issue 1 to update its content.

HISTORICAL RECORD

This standard supersedes the following:

Naval Engineering Standard (NES) 822 Part 2 Issue 2 dated December 1993.

Ministry of Defence

Naval Engineering Standard

NES 822 Part 2 Issue 2 (Reformatted) December 1993

REQUIREMENTS FORNICKEL CHROMIUM MOLYBDENUM NIOBIUM ALLOY 625

PART 2

SAND CASTINGS AND INGOTS

This NES Supersedes

NES 822 PART 2 ISSUE 1

Record of Amendments

AMDT INSERTED BY DATE

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NAVAL ENGINEERING STANDARD 822

REQUIREMENTS FOR NICKEL CHROMIUM MOLYBDENUM

NIOBIUM ALLOY 625

PART 2

ISSUE 2 (REFORMATTED)

SAND CASTINGS AND INGOTS

The issue and use of this Standard

is authorized for use in MOD contracts

by MOD(PE) Sea Systems and

the Naval Support Command

ECROWN COPYRIGHT

Published by:

Director of Naval ArchitectureProcurement Executive, Ministry of DefenceFoxhill, Bath BA1 5AB

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NES 822Part 2

Issue 2 (Reformatted)

iii

SCOPE

1. This NES states the requirements for the manufacture, inspection and testing of sand castingsand ingots in Nickel Chromium Molybdenum Niobium Alloy 625.

NES 822Part 2Issue 2 (Reformatted)

iv

NES 822Part 2


v

FOREWORD

Sponsorship

1. This Naval Engineering Standard (NES) is sponsored by the Procurement Executive, Ministryof Defence, Director Naval Architecture (DNA), Section NA 115.

2. This NES comprises:Requirements for Nickel Chromium Molybdenum Niobium Alloy 625

a. Part 1: Centrifugal Castings

b. Part 2: Sand Castings

3. If it is found to be unsuitable for any particular requirement the Sponsor is to be informed inwriting of the circumstances with a copy to Director Naval Architecture (DNA), NA 145.

4. Any user of this NES either within MOD or in industry may propose an amendment to it.Proposals for amendments that are not directly applicable to a particular contract are to bemade to the Sponsor of the NES and those directly applicable to a particular contract are tobe dealt with using existing procedures or as specified in the contract.

5. No alteration may be made to this NES except by the issue of an authorized amendment.

6. Unless otherwise stated, reference in this NES to approval, approved, authorized or similarterms means by the Ministry of Defence.

7. Any significant amendments that may be made to this NES at a later date will be indicatedby a vertical sideline. Deletions will be indicated by 000 appearing at the end of the lineinterval.

8. This NES has been reissued to reflect the changes in technical requirements.

Conditions of Release

General

9. This Naval Engineering Standard (NES) has been prepared for the use of the Crown and ofits contractors in the execution of contracts for the Crown. The Crown hereby excludes allliability (other than liability for death or personal injury) whatsoever and howsoever arising(including but without limitation, negligence on the part of the Crown, its servants or agents)for any loss or damage however caused where the NES is used for any other purpose.

10. This document is Crown Copyright and the information herein may be subject to Crown orthird party rights. It is not to be released, reproduced or published without written permissionof the MOD.

11. The Crown reserves the right to amend or modify the contents of this NES without consultingor informing any holder.

MOD Tender or Contract Process

12. This NES is the property of the Crown and unless otherwise authorized in writing by the MODmust be returned on completion of the contract, or submission of the tender, in connectionwith which it is issued.


vi

13. When this NES is used in connection with a MOD tender or contract, the user is to ensure thathe is in possession of the appropriate version of each document, including related documents,relevant to each particular tender or contract. Enquiries in this connection may be made ofthe local MOD(PE) Quality Assurance Representative or the Authority named in the tenderor contract.

14. When NES are incorporated into MOD contracts, users are responsible for their correctapplication and for complying with contracts and any other statutory requirements.Compliance with an NES does not of itself confer immunity from legal obligations.

Related Documents

15. In the tender and procurement processes the related documents listed in each section andAnnex A can be obtained as follows:

a. British Standards British Standards Institution,389 Chiswick High Road,London W4 4AL

b. Defence Standards Directorate of Standardization and Safety Policy,Stan 1, Kentigern House, 65 Brown Street,Glasgow G2 8EX

c. Naval Engineering Standards CSE3a, CSE Llangennech, Llanelli,Dyfed SA14 8YP

d. Other documents Tender or Contract Sponsor to advise.

Note: Tender or Contract Sponsor can advise in cases of difficulty.

16. All applications to Ministry Establishments for related documents are to quote the relevantMOD Invitation to Tender or Contract Number and date, together with the sponsoringDirectorate and the Tender or Contract Sponsor.

17. Prime Contractors are responsible for supplying their subcontractors with relevantdocumentation, including specifications, standards and drawings.

Health and Safety

Warning

18. This NES may call for the use of processes, substances and/or procedures that may be injuriousto health if adequate precautions are not taken. It refers only to technical suitability and inno way absolves either the supplier or the user from statutory obligations relating to healthand safety at any stage of manufacture or use. Where attention is drawn to hazards, thosequoted may not necessarily be exhaustive.

NES 822Part 2


vii

CONTENTSPage No

TITLE PAGE i. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SCOPE iii. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

FOREWORD v. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Sponsorship v. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Conditions of Release v. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

General v. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .MOD Tender or Contract Process v. . . . . . . . . . . . . . . . . . . . . . . . . .

Related Documents vi. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Health and Safety vi. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Warning vi. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

CONTENTS vii. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SECTION 1. PHYSICAL CHARACTERISTICS 1.1. . . . . . . . . . . . .1.1 Ingots 1.1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.2 Castings 1.1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.3 Quality of Material 1.1. . . . . . . . . . . . . . . . . . . . . . . . . . .1.4 Composition 1.2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

TABLE 1.1 CHEMICAL COMPOSITION 1.2. . . . . .

SECTION 2. HEAT TREATMENT 2.1. . . . . . . . . . . . . . . . . . . . . . . . .

SECTION 3. MECHANICAL PROPERTIES 3.1. . . . . . . . . . . . . . . .TABLE 3.1 MECHANICAL PROPERTIES 3.1. . . . .

SECTION 4. CLASSIFICATION 4.1. . . . . . . . . . . . . . . . . . . . . . . . . .

SECTION 5. QUALITY ASSURANCE DOCUMENTATION 5.1. . .

SECTION 6. TEST METHODS 6.1. . . . . . . . . . . . . . . . . . . . . . . . . . . .6.1 Destructive Tests 6.1. . . . . . . . . . . . . . . . . . . . . . . . . . . . .6.2 Analysis 6.1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6.3 Mechanical Tests 6.1. . . . . . . . . . . . . . . . . . . . . . . . . . . . .6.4 Dimensional Check 6.1. . . . . . . . . . . . . . . . . . . . . . . . . . .6.5 Visual-Optical 6.1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6.6 Liquid Penetrant 6.1. . . . . . . . . . . . . . . . . . . . . . . . . . . . .6.7 Radiography 6.1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6.8 Radiographic Examination of Non-Designated

Regions on a Sample Basis 6.2. . . . . . . . . . . . . . . . . . . . .6.9 Pressure Tests 6.2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

FIGURE 6.1 CAST KEEL BAR FOR TENSILETEST PIECE 6.3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .


viii

SECTION 7. ACCEPTANCE STANDARDS 7.1. . . . . . . . . . . . . . . . .7.1 Destructive Examination Standards 7.1. . . . . . . . . . . . .7.2 Analysis 7.1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7.3 Mechanical Tests 7.1. . . . . . . . . . . . . . . . . . . . . . . . . . . . .7.4 Non-Destructive Examination Standards 7.1. . . . . . . .7.5 Visual-Optical 7.1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7.6 Liquid Penetrant 7.1. . . . . . . . . . . . . . . . . . . . . . . . . . . . .7.7 Radiography 7.1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7.8 Pressure Tests 7.1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SECTION 8. DEFECTS AND RECTIFICATION OF DEFECTS 8.18.1 Defects 8.1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8.2 Rectification of Defects 8.1. . . . . . . . . . . . . . . . . . . . . . . .8.3 Rectification of Surface Defects by Blending 8.1. . . . . .8.4 Rectification of Dimensional Defects by Weld

Deposition 8.1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8.5 Rectification of Surface and Sub-Surface Defects

by Welding 8.1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8.6 Limits on Individual Repairs 8.2. . . . . . . . . . . . . . . . . . .8.7 Limits on Weld Repairs 8.2. . . . . . . . . . . . . . . . . . . . . . .8.8 Impregnation of Pressure Castings 8.2. . . . . . . . . . . . . .8.9 Special Repairs 8.3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SECTION 9. IDENTIFICATION OF INGOTS AND CASTINGS 9.19.1 Ingots 9.1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9.2 Castings 9.1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SECTION 10. PACKAGING 10.1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

ANNEX A. RELATED DOCUMENTS A.1. . . . . . . . . . . . . . . . . . . .

ANNEX B. DEFINITIONS AND ABBREVIATIONS B.1. . . . . . . .

ALPHABETICAL INDEX

NES 822Part 2


1.1

1. PHYSICAL CHARACTERISTICS

1.1 Ingots

a. Ingots are produced from pure virgin metal, master alloys or from selected scraprefined by the argon oxygen decarburization (AOD) process. The virgin metalsand master alloys are to be:

Nickel complying with the chemical compositionrequirements of BS 375—Grade R99.9 or anequivalent specification which is at least asrestrictive.

Chromium high-purity electrolytic or high-purity thermicchromium or reactor-grade ferro-chromium.

Molybdenum pure molybdenum, ferro-molybdenum or, for AODonly, molybdenum oxide.

Niobium nickel niobium or ferro-niobium master alloys.

Iron high-purity electrolytic iron.

The ferro-chromium, molybdenum and niobium master alloys are to be used incontrolled amounts related to the composition limits of the product defined inClause 1.4a.

b. If any other metal refining process is proposed for the manufacturing of ingots,details are to be forwarded to the Acceptance Authority, and approval obtainedbefore manufacture commences. The chemical composition of ingots is toconform to TABLE 1.1.

1.2 Castings

a. Castings are to be made from any combination of virgin metals, master alloys(as detailed in Clause 1.1a.), the manufacturer’s own approved scrap (see ClauseB1) and ingots so that the final chemical composition conforms to TABLE 1.1.

1.3 Quality of Material

a. No further additions are to be made to a cast after the final analytical samplehas been taken.

b. No titanium additions are to be made if air melting is used.

NOTE: Melt contamination can be substantially reduced by using rammed basiclinings for electric furnaces. Ladles with silicate linings are to be given analumina wash. Silicious or graphite crucibles are not to be used.


1.2

1.4 Composition

a. The chemical composition of both ingots and castings is given in TABLE 1.1.

ElementPer cent by Weight

ElementNot Less Than Not More Than

Nickel 58.0

Chromium 20.0 23.0

Molybdenum 8.0 10.0

Niobium + Tantalum 3.15 4.15

Iron 5.0

Cobalt 1.0

Manganese 0.5

Silicon 0.5

Aluminium 0.4

Titanium 0.4

Carbon 0.03

Tin 0.05

Lead 0.05

Phosphorous 0.015

Sulphur 0.015

Calcium 0.005

TABLE 1.1 CHEMICAL COMPOSITION

NES 822Part 2


2.1

2. HEAT TREATMENT

a. Castings and test pieces are to be solution heat treated at 1150−1220° C for 1hour/25mm section thickness (2 hours minimum) and then air cooled or waterquenched. Separately cast test pieces are to be heat treated in the same furnacebatch as the castings they represent.

b. Sufficient accurately calibrated thermocouples are to be provided to ensurecomplete coverage, uniform temperature and adequate temperature history.Sulphur content of furnace atmosphere is to be less than 0.005g/m3.

c. Should a casting be weld repaired (see Clauses 8.2a. to 8.7b.) solution heattreatment is not to be carried out until the welding operation is completed.


2.2

NES 822Part 2


3.1

3. MECHANICAL PROPERTIES

a. The mechanical properties at room temperature and impact strength at−46° Cof solution heat treated test pieces (as specified in Clause 6.3a.) are to be asdetailed in TABLE 3.1.

Tensile Strength 0 2% Proof StressElongation

on 5 65 S ImpactTensile Strength 0.2% Proof Stress on 5.65Gauge Length

So Impact

Strength

N/mm2 N/mm2 Per cent Joules

Min Min Min Min

500 250 25 27

TABLE 3.1 MECHANICAL PROPERTIES


3.2

NES 822Part 2


4.1

4. CLASSIFICATION

a. The classification of castings is as defined in NES 863.


4.2

NES 822Part 2


5.1

5. QUALITY ASSURANCE DOCUMENTATION

a. Each consignment of ingots or castings is to be accompanied by QualityAssurance Documentation giving the actual results of the tests required inSection 6. together with a Certificate of Compliance with the acceptancestandards detailed in Section 7.


5.2

NES 822Part 2


6.1

6. TEST METHODS

6.1 Destructive Tests

6.2 Analysis

a. In addition to the normal melt-control analysis, a full chemical analysis is to bemade from a sample piece taken from each cast for ingots and for castings.

6.3 Mechanical Tests

a. Tests bars are to be cast to comply with FIGURE 6.1, from the same cast as thecastings they represent, and be heat treated to comply with Clause 2.a. Tensiletests are to comply with BS EN 10002. Charpy V-Notch Test are to comply withBS EN 10045−1.

NOTE: It is advisable to cast three test bars to represent each cast to enablere-testing if necessary to meet the acceptance standard details inClause 7.3a.

b. Reference diagrams according to NES 863 are to be provided by the purchaserfor all Class I and Class II castings to show Critical Test Regions and TestRegions which are to be subjected to non-destructive testing (NDT).

6.4 Dimensional Check

a. All castings are to be fully dimensionally checked where practicable, to ensurethat they comply with NES 863.

6.5 Visual-Optical

a. All castings are to be 100% visually inspected, assisted where necessary, by theuse of ¢5 magnification optics. All imperfections are to be identified andrecorded.

6.6 Liquid Penetrant

a. It is recommended that a 100% liquid penetrant examination, in compliancewith NES 729 Part 4, is carried out on all Class I and Class II castings before anymachining operations are commenced to prevent nugatory work.

b. A 100% liquid penetrant inspection is to be undertaken on all surfaces of ClassI and Class II castings with the surfaces examined in their finished condition.

c. If the casting dimensions are such that the internal surface is not accessible for100% examination, then the extent of examination is to be agreed betweenpurchaser and manufacturer.

6.7 Radiography

a. Critical Test Regions and Test Regions are to be subject to 100% radiographicexamination to comply with NES 729, Part 1. All sub-surface imperfections areto be identified for subsequent assessment in compliance with NES 863.


6.2

6.8 Radiographic Examination of Non-Designated Regions on a Sample Basis

a. In certain circumstances examination by radiography on a sample basis may bespecified by contract or drawings to establish that a satisfactory general qualityof product is being supplied. Typical examples are:

(1) lowly stressed Class II castings;

(2) sample positions on large Class II or Class III castings;

(3) batch supply of Class III castings.

6.9 Pressure Tests

a. When stated in the contract the castings are to be subjected to the specifiedwater pressure test for a minimum period of 15 minutes. Certain castings mayrequire longer periods of pressure testing. When necessary this will be specifiedin the contract.

NES 822Part 2


6.3

FIGURE 6.1 CAST KEEL BAR FOR TENSILE TEST PIECE


6.4

NES 822Part 2


7.1

7. ACCEPTANCE STANDARDS

7.1 Destructive Examination Standards

7.2 Analysis

a. Each analysis, determined in compliance with Clause 6.2a. is to conform toTABLE 1.1.

7.3 Mechanical Tests

a. The mechanical properties determined in compliance with Clause 6.3a. are toconform to the requirements of TABLE 3.1. Should an original test bar fail tomeet the requirements, two further test bars from the same cast may be tested.Both results are to conform to the requirements of TABLE 3.1.

7.4 Non-Destructive Examination Standards

7.5 Visual-Optical

a. On visual-optical inspection (Clause 6.4a.) the finished condition of all surfacesis to be clean and free from cracks or linear defects. Rounded forms of surfacedefects are unacceptable in Critical Test Regions and Test Regions but may beacceptable in Non-Designated Regions at the discretion of the AA.

b. The surface finish is to meet the standard specified in the contract and thedrawings.

7.6 Liquid Penetrant

a. Indications of cracks, hot tears or chain-like porosity and surface oxideinclusions in linear formations are not acceptable.

b. Indications arising from porosity and surface oxide inclusions in non-linearformations are to be assessed as follows:

(1) Isolated pinpoint porosity (minimum separation 50mm) is acceptableexcept in areas where sealing of a housing against a running shaft isrequired, eg pump glands, propeller shaft seals etc, and in flexiblecouplings.

(2) Clustered pinpoint porosity and other defects are acceptable provided thatthe maximum size of any indications does not exceed 3mm diameter bleedout and the sum of the diameters of all indications in an area of 70 ¢70mm does not exceed 24mm.

NOTE: The indications identified in Clause 7.6b.(1) and (2) are acceptableproviding that the immediate area of the castings is acceptable whenexamined for sub-surface defects.

7.7 Radiography

a. See NES 863 Clauses 0905−0910.

7.8 Pressure Tests

a. Each casting is to show no evidence of leakage.


7.2

NES 822Part 2


8.1

8. DEFECTS AND RECTIFICATION OF DEFECTS

8.1 Defects

a. Any casting may be rejected for defects discovered during subsequentmachining, notwithstanding that the casting had been passed previously asconforming to this NES.

8.2 Rectification of Defects

a. All castings may be weld repaired in accordance with NES 823 within the limitsdetailed in this NES.

8.3 Rectification of Surface Defects by Blending

a. Unacceptable surface defects may be blended out by an approved process,providing the resulting depression does not reduce the contract drawing sectionthickness by more than 5mm for section thickness over 50mm, or 10% of sectionthicknesses up to and including 50mm. The depression sides and ends are to besmoothly blended out by a minimum radius of three times the maximum depthof blending and the edge formed with the surface is also to be faired smooth. Theremaining section thickness in way of the depression is to be free fromsub-surface defects as revealed by radiography or ultrasonics, in Critical TestRegions and Test Regions. The total area subjected to blending, including thearea affected by the fairing, is not to exceed 10% of any designated region or 20%or any non-designated region.

NOTE: Blending out of surface defects is preferable to weld repair wheneverpossible.

8.4 Rectification of Dimensional Defects by Weld Deposition

a. On section thicknesses 12mm and above correction of casting dimensions andmachining errors may be made by weld deposition on both the internal andexternal surfaces using an approved procedure for the material concerned inaccordance with NES 823 and is to be within the following limits:

(1) Weld deposition thickness to be restricted to 20% of contract drawingsection thickness from 12mm to 50mm and to 10mm above 50mm sectionthickness.

(2) Area of weld deposition in Critical Test Regions and Test Regions to berestricted to 10% of the surface area of the region, not including flangethicknesses and webs, subject to any limitations imposed by Clause 8.7a.

(3) Area of weld deposition in non-designated regions is to be restricted to20% of the surface area of the region not including flange thickness andwebs.

b. Weld build-up exceeding the tolerance on contract drawing section thickness isto be a reason for rejection.

8.5 Rectification of Surface and Sub-Surface Defects by Welding

a. Unacceptable surface defects which cannot be blended out within thelimitations of Clause 8.3a. and unacceptable sub-surface defects may berepaired by welding using an approved procedure for the material concerned incompliance with NES 823 and within the following limits:


8.2

(1) Area of excavation in Critical Test Regions and Test Regions is to berestricted to 10% of the inner or outer surface area of the region, notincluding flange thicknesses and webs, subject to any limitations imposedby Clause 8.7a.

(2) Area of excavation in non-designated regions is to be restricted to 20% ofthe inner or outer surface area of the region, not including flangethicknesses and webs.

8.6 Limits on Individual Repairs

a. Any individual repair in Critical Test Regions shall not exceed 5% of the testarea containing the defect. In Test Regions any individual repair shall notexceed 10% of test area containing the defect.

8.7 Limits on Weld Repairs

a. The total area of weld repairs from all causes, eg dimensional correction, surfaceand sub-surface defects is to be within the following limits:

(1) Total weld repair area of Class I and Class II castings is not to exceed 10%of the surface area of the casting, excluding flange thicknesses and webs.

(2) The total weld repair area of Class III castings is not to exceed 20% of thesurface area of the casting excluding flange thicknesses and webs.

b. After all weld repair has been completed and the casting accepted in compliancewith Section 7. the casting is to be heat treated to comply with Section 2.

c. After heat treatment all weld repaired areas are to be liquid penetrant tested tocomply with Clause 6.6a. over an area contained by a boundary drawn at aminimum distance of 50mm from the weld boundary. Repaired areas are alsoto be radiographed in accordance with Clause 6.7a.

d. If after three attempts, the weld repair fails to meet the acceptance standardbefore or after heat-treatment, the casting is to be rejected. No casting is to beheat treated more than three times.

8.8 Impregnation of Pressure Castings

a. Impregnation will not be permitted as a recovery procedure for Class I castings.

b. Impregnation in compliance with Def Stan 03−1 is a recognized recoveryprocedure for Class II and III castings suffering from leakage during pressuretesting due to micro-porosity. The procedure may be applied to comply with therequirements of Clause 8.8c.

c. Class II and Class III castings may be impregnated but only with the writtenapproval of the Acceptance Authority and providing that the area of leakagenecessitating remedial action does not exceed 10% of:

(1) the test region containing the defect in Class II castings and

(2) the total area pressure tested in non-designated test regions in Class II andIII castings.

d. Pressure tests are to be carried out on the impregnated castings to comply withClause 6.9a., acceptance being in compliance with Clause 7.8a. Heat treatmentis not to be carried out after impregnation.

NES 822Part 2


8.3

8.9 Special Repairs

a. Where the repairs necessary to meet the acceptance standards are moreextensive than are permitted by this specification and if it is considered thateffective economical repair is possible the QAR may submit the contractorsrepair proposals in compliance with NES 823 to the Acceptance Authority fora decision.


8.4

NES 822Part 2


9.1

9. IDENTIFICATION OF INGOTS AND CASTINGS

9.1 Ingots

a. Each ingot is to be marked with the legend ‘625’ and a unique cast numberstamped or embossed in easily discernible letters. The unique cast number is topositively identify the ingot to its Quality Assurance Documentation.

9.2 Castings

a. Each casting is to be clearly identifiable during manufacture and bepermanently marked for identification during service life with the followingdetails:

(1) Pattern or Ships Identity Number plus NES 822 Part 2.

(2) Class of casting, ie C I, C II, C III (see NES 863).

(3) The legend ‘625’.

(4) The unique cast number which will relate the casting to its QualityAssurance Documentation.

b. The markings detailed in Clause 9.2a. are to be stamped, engraved orvibro-etched in the position indicated on the drawing. Markings are to be asconspicuous as the nature of the casting allows and provision is to be made fortransferring identification markings during manufacture so that traceability ismaintained throughout the service life of a casting. The markings are not to bemade on the highly stressed regions, eg Critical Test Regions of the casting.

c. Where difficulty is being experienced in satisfactorily applying identificationsymbols, the problem is to be resolved by consulting the AcceptanceAuthority/QAR.


9.2

NES 822Part 2


10.1

10. PACKAGING

a. Except where otherwise stated in the contract, packaging is to comply with thecontractor’s normal practice subject to the affixing of a trade warning label andthe addition of the following identification details on each package or case:

(1) Description of castings.

(2) Quantity.

(3) Contract Number.


10.2

NES 822Part 2


A.1 ANNEX A.

ANNEX A.

RELATED DOCUMENTS

A.1 The following documents and publications are referred to in this NES:

See Clause

BS 375 Specification for refined nickel 1.1a.

BS EN 10002 Tensile testing of metallic materials B.1, 6.3a.

BS EN 10045−1 Charpy impact test on metallic materialsTest methods (V- and U-notch)

6.3a.

DEF STAN 03−1 Impregnation of Porous Castings 8.8b.

NES 729 Requirements for Non-DestructiveExamination MethodsPart 1: Radiographic 6.7a.

Part 4: Liquid Penetrant B.1, 6.6a.

NES 823 Requirements for the Welding of Cast NickelAlloy 625

8.2a., 8.4a.,8.5a., 8.9a.

NES 863 Requirements for the Classification,Dimensions, Tolerances and GeneralStandards of Acceptance for Copper andNickel Alloy Castings

4.a., 6.3b.,6.4a., 6.7a.,7.7a., 9.2a.


A.2ANNEX A.

NES 822Part 2


B.1 ANNEX B.

ANNEX B.

DEFINITIONS AND ABBREVIATIONS

B.1 For the purpose of this NES the following definitions apply:

Acceptance Authority (AA) The Acceptance Authority is as specified inthe Contract. Where this is not known by theContractor, enquiries are to be forwarded toDNA, Section NA 115, Foxhill, Bath.

Approved Scrap Derived from clean Cast Nickel ChromiumMolybdenum Niobium Alloy 625 foundryarisings, the composition of which has beenestablished with regard to the complete rangeof both the alloying elements and impurityelements and segregated and identifiable tothe satisfaction of the MOD QualityAssurance Representative (QAR)/AcceptanceAuthority.

Cast A product of one furnace melt orCast A product of one furnace melt or

the product of one crucible melt or

the product of a number of furnace orcrucible melts where such are aggregated andmixed prior to sampling.

Cast A product of one furnace meltorth d t f ibl ltthe product of one crucible meltorthe product of a number of furnace orthe product of a number of furnace orcrucible melts where such are aggregated andmixed prior to sampling.

Contractor The Firm, Company, Organization, orEstablishment working within the scope ofthis NES.

Ingot A mass of metal of proportions to suit theFounder’s re-melting requirements.

Pinpoint Porosity Any circular bleed out of less than 0.5mmdiameter revealed during liquid penetrantexamination in accordance with NES 729,Part 4.

Quality AssuranceRepresentative (QAR)

Any officer duly authorized to act on behalf ofthe AA and the Project Manager.

S0 The cross-sectional area of the gauge in atensile test piece, before testing, as detailed inBS EN 10002.


B.2ANNEX B.

NES 822Part 2


INDEXINDEX.1

ALPHABETICAL INDEX

AAcceptance standards, 7.1

Analysis, 6.1, 7.1

Approved scrap, 1.1, B.1

BBlending, 8.1

CCastings, 1.1, 9.1

Certificate of compliance, 5.1

Chemical composition, 1.2

Cracks, 7.1

DDefects, 8.1

Definitions, B.1

Destructive acceptance standards, 7.1

Destructive tests, 6.1

Dimension check, 6.1

HHeat treatment, 2.1, 8.2

IIdentification of castings, 9.1

Identification of ingots, 9.1

Impregnation, 8.2

Ingots, 1.1, 9.1

LLinear defects, 7.1

Liquid penetrant, 6.1, 7.1

MMechanical properties, 3.1

Mechanical tests, 6.1


INDEX INDEX.2

NNon-destructive acceptance standards, 7.1

Non-destructive test, 6.1, 6.2, 7.1

OOptical inspection, 6.1, 7.1

PPackaging, 10.1

Physical characteristics, 1.1, 1.2

Pinpoint porosity, 7.1, B.1

Pressure tests, 6.2, 7.1, 8.2

Proof stress, 3.1

QQuality Assurance, 5.1

Quality of material, 1.1

RRadiography, 6.1, 6.2, 7.1, 8.1

Rectification of defects, 8.1, 8.2

SSample examination, 6.2

Special repairs, 8.3

TTensile strength, 3.1

Tensile test, 6.1

Test pieces, 6.1

Tests, 6.1, 6.2

VVisual inspection, 6.1, 7.1

WWeld deposition, 8.1

Weld repair, 8.1, 8.2

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