NB/T 47014-2023Welding procedure qualification for pressure equipments (English PDF)

Foreword

This document was issued on 28 December 2023 by the National Energy Administration of the PRC and takes effect on 28 June 2024.

It is a NB/T standard: recommended rather than compulsory, but it is the text a Chinese reviewer applies when assessing a submission.

It is classified under ICS 25.160.10, Chinese classification J 33.

It replaces NB/T 47014-2011, which is superseded.

This document has been drafted in accordance with the rules given in GB/T 1.1-2020, Directives for standardization - Part 1: Rules for the structure and drafting of standardizing documents.

This document replaces NB/T 47014-2011, Welding procedure qualification for pressure equipments. Compared with NB/T 47014-2011, besides structural adjustments and editorial changes, the main technical changes are as follows.

a) Welding procedure qualification of electron beam welding has been added (see Clause 1, Table 5 and 6.1.5.6).

b) Welding procedure qualification of zirconium materials has been added (see Table 1).

c) The terms buttering, supplemental filler metal and heat input of strip surfacing welding have been added; the definitions of welding procedure qualification, welding defect and imperfection have been revised; and the expression welding line energy has been uniformly changed to welding heat input throughout the document (see Clause 3).

d) The class (group) numbers of the base metal grades L415, L485, 10Ni3MoVD and TA2 have been adjusted; gas cylinder steels such as HP295 have been deleted; and the austenitic stainless steel base metal grade 015Cr21Ni26Mo5Cu2 has been deleted from class Ni-5 (see Table 1, and Table 1 of the 2011 edition).

e) The base metal grades Q420R, 06Ni9D(R), GB/SA516Gr70, GB/SA537Cl1 and GB/SA387Gr12Cl2, together with zirconium base metal grades, have been added (see Table 1).

f) Material class (group) numbers for zirconium materials have been added (see Table 1).

g) The designations of aluminium welding wires have been revised (see Table 3).

h) The separate class numbers of submerged-arc welding wires and of fluxes have been deleted; submerged-arc welding wire and flux are now classified as a combination (see Table 4, and Table 4 and Table 5 of the 2011 edition).

i) The dedicated welding procedure qualification factors of the various welding processes have been revised: the groove form and the gap of electrogas welding have been added as supplementary factors; a change of the type or polarity of the welding current in shielded metal arc welding has been added as an essential factor; and the proportional requirements for mixed shielding gases have been revised (see Table 5).

j) The following provisions on the maximum thickness qualified for the weldment have been deleted: post weld heat treatment of the test coupon above the upper transformation temperature, except for gas welding, stud arc welding and friction welding; short-circuiting transfer gas metal arc welding when the coupon thickness is less than 13 mm; and short-circuiting transfer gas metal arc welding when the weld metal thickness of the coupon is less than 13 mm (see Table 10 of the 2011 edition).

k) The preparation of butt weld test coupons of large-diameter pipes and the location of the test specimens have been added (see 6.3.5.3 and Figure 3).

l) Provisions have been added for the impact test of welded joints performed at the test temperature required by the design drawing, together with the acceptance indexes of the impact absorbed energy of welded joints of different steel grades [see 6.4.1.7.3 a)].

m) The acceptance index of the impact absorbed energy of boiler welded joints has been revised [see 6.4.1.7.3 b)].

n) The welding procedure factors that require requalification of the surfacing metal have been revised (see Table 15).

o) The sampling location of tubular surfacing test coupons has been revised (see 7.3.1.3.1).

p) Welding procedure qualification of butt welds with a buttering layer has been added (see Annex C).

q) The welding procedure qualification rule for stainless steel-steel clad plates welded with the base layer first and the cladding layer afterwards has been revised, that is, the base layer weld shall be qualified as a combination weld [see D.2.3 a) and D.3.2.1].

r) A welding procedure qualification rule has been added for welding the cladding layer first and the base layer afterwards [see D.2.3 b) and D.3.3].

s) The qualification rule relating the outside diameter of the test coupon to the outside diameter of the production pipe has been deleted [see D.4.2.2 a) of the 2011 edition].

t) The qualification rule for the ligament width has been revised (see E.5.3).

u) In the examination of tube-to-tubesheet welding test coupons, the measurement of the fillet weld throat thickness has been changed to the measurement of the weld leg size l, and tube-head test coupons arranged in a square pitch have been added (see E.5.4.5 and Figure E.2).

v) The recommended table forms of the preliminary welding procedure specification and of the welding procedure qualification report have been revised, and the recommended table forms of the tube-to-tubesheet welding procedure card and of the additional qualification report for tube-to-tubesheet welding have been deleted (see Annex G, and Table F.3 and Table F.4 of the 2011 edition).

Attention is drawn to the possibility that some of the contents of this document may be the subject of patent rights. The issuing body of this document assumes no responsibility for identifying patent rights.

This document was proposed by and is under the jurisdiction of the National Technical Committee on Boilers and Pressure Vessels of Standardization Administration of China (SAC/TC 262).

Drafting organizations of this document: Hefei General Machinery Research Institute Co., Ltd.; China Special Equipment Inspection and Research Institute; Lanzhou LS Heavy Equipment Co., Ltd.; Dalian Boiler and Pressure Vessel Inspection and Testing Research Institute Co., Ltd.; Fushun Machinery and Equipment Manufacturing Co., Ltd.; SINOPEC Engineering Construction Co., Ltd.; Shanghai Boiler Works Co., Ltd.; Sinopec Nanjing Chemical Industry Machinery Co., Ltd.; China Petroleum First Construction Co., Ltd.; PetroChina Pipeline Research Institute Co., Ltd.; Shanghai Special Equipment Supervision and Inspection Technical Research Institute; State Administration for Market Regulation; Harbin Boiler Works Co., Ltd.; CFHI Dalian Nuclear Power Petrochemical Co., Ltd.

Main drafters of this document: Fang Wunong, Li Jun, Zhang Jianxiao, Guo Chuanjiang, Hu Xihai, Dou Wanbo, Ge Zhaowen, Wang Jinguang, Wang Jiongxiang, Zhu Ning, Nie Min, Sui Yongli, Ji Fang, Gu Fuming, Chang Yanyan, Li Yinan, Yuan Jijun, Guo Guangfei, Yang Guoyi and Jiang Haiyi.

The interpretation of this document is the responsibility of the National Technical Committee on Boilers and Pressure Vessels of Standardization Administration of China (SAC/TC 262).

The previous editions of this document and of the documents it replaces are: JB 4708-1992; JB 4708-2000; NB/T 47014-2011.

1 Scope

NB/T 47014-2023 is the Chinese standard for welding procedure qualification on pressure equipment, replacing the 2011 edition. Before a vessel, boiler or pressure pipe may be welded in production, the procedure must be proved: a test coupon is welded under stated conditions, then examined and tested, and the results establish the range of production welding the procedure covers. This standard defines that process. It sets the general requirements on who may qualify a procedure and on the preliminary welding procedure specification, the test coupon and its preparation, and the record that results. It groups base materials into material numbers and groups, and filler materials into their own classification, since a qualification made on one member of a group normally covers the others. The heart of the standard is the treatment of qualification variables: for each welding process it lists the essential variables that invalidate a qualification when changed, the supplementary essential variables that apply when impact testing is required, and the non-essential variables that may be changed without requalifying. The mechanical and non-destructive testing of the coupon follows - tensile, bend, impact, hardness, macro examination and, where the product demands it, corrosion testing - with the acceptance criteria and the retest rules. Qualification for overlay and cladding, for tube-to-tubesheet welds and for repair welding is covered separately, and the appendices give the forms on which the specification and the qualification record are written. It applies across Chinese pressure equipment manufacture.

This document specifies the rules, the test methods and the acceptance indexes for the welding procedure qualification of pressure equipment, namely boilers, pressure vessels and pressure piping.

This document applies to the welding procedure qualification of the following welding processes: gas welding, shielded metal arc welding, submerged arc welding, tungsten inert gas arc welding, gas metal arc welding including flux-cored wire arc welding, electroslag welding, plasma arc welding, friction welding, electrogas welding, stud arc welding and electron beam welding.

This document does not apply to the welding procedure qualification of gas cylinders.

2 Normative references

The contents of the following documents constitute indispensable provisions of this document through the normative references made to them in the text. For dated references, only the edition corresponding to that date applies to this document. For undated references, the latest edition of the referenced document, including all amendments, applies to this document.

GB/T 150.2, Pressure vessels - Part 2: Materials.

GB/T 151, Heat exchangers.

GB/T 228 (all parts), Metallic materials - Tensile testing.

GB/T 229, Metallic materials - Charpy pendulum impact test method.

GB/T 699, Quality carbon structural steels.

GB/T 700, Carbon structural steels.

GB/T 711, Hot-rolled quality carbon structural steel plates and strips.

GB/T 713, Steel plates for boilers and pressure vessels.

GB/T 1176, Cast copper and copper alloys.

GB/T 1527, Drawn copper and copper alloy tubes.

GB/T 1591, High strength low alloy structural steels.

GB/T 2040, Copper and copper alloy sheets and plates.

GB/T 2054, Nickel and nickel alloy plates.

GB/T 2653, Bend test methods on welded joints.

GB/T 2882, Nickel and nickel alloy tubes.

GB/T 2965, Titanium and titanium alloy bars.

GB/T 3077, Alloy structural steels.

GB/T 3087, Seamless steel tubes for low and medium pressure boilers.

GB/T 3091, Welded steel pipes for low pressure liquid transport.

GB/T 3274, Hot-rolled plates and strips of carbon structural steels and of high strength low alloy structural steels.

GB/T 3280, Cold-rolled stainless steel plates and strips.

GB/T 3375, Welding terminology.

GB/T 3531, Steel plates for low temperature pressure vessels.

GB/T 3620.1, Titanium and titanium alloys - Designations and chemical compositions.

GB/T 3621, Titanium and titanium alloy sheets and plates.

GB/T 3624, Titanium and titanium alloy seamless tubes.

GB/T 3625, Titanium and titanium alloy tubes for heat exchangers and condensers.

GB/T 3670, Copper and copper alloy covered electrodes.

GB/T 3880 (all parts), Wrought aluminium and aluminium alloy plates, sheets and strips for general engineering.

GB/T 4237, Hot-rolled stainless steel plates and strips.

GB/T 4423, Copper and copper alloy drawn bars and rods.

GB/T 4435, Nickel and nickel alloy bars.

GB/T 4437.1, Aluminium and aluminium alloy hot extruded tubes - Part 1: Seamless round tubes.

GB/T 5310, Seamless steel tubes for high pressure boilers.

GB/T 6479, Seamless steel tubes for high pressure chemical fertilizer equipment.

GB/T 6614, Titanium and titanium alloy castings.

GB/T 6892, Wrought aluminium and aluminium alloy extruded profiles for general engineering.

GB/T 6893, Aluminium and aluminium alloy drawn or rolled tubes.

GB/T 8163, Seamless steel tubes for liquid transport.

GB/T 8769, Zirconium and zirconium alloy bars and wires.

GB/T 8890, Seamless copper alloy tubes for heat exchangers.

GB/T 9460, Copper and copper alloy welding wires.

GB/T 9711, Petroleum and natural gas industries - Steel pipes for pipeline transportation systems.

GB/T 9948, Seamless steel tubes for petroleum cracking.

GB/T 11352, Carbon steel castings for general engineering purposes.

GB/T 12228, General purpose valves - Technical specification of carbon steel forgings.

GB/T 12229, General purpose valves - Technical specification of carbon steel castings.

GB/T 12230, General purpose valves - Technical specification of stainless steel castings.

GB/T 12771, Welded stainless steel pipes for liquid transport.

GB/T 13237, Cold-rolled quality carbon structural steel plates and strips.

GB/T 13296, Seamless stainless steel tubes for boilers and heat exchangers.

GB/T 13401, Steel butt-welding pipe fittings - Technical specification.

GB/T 13814, Nickel and nickel alloy covered electrodes.

GB/T 14845, Titanium plates for plate heat exchangers.

GB/T 14976, Seamless stainless steel pipes for liquid transport.

GB/T 15008, Corrosion-resisting alloy bars.

GB/T 15620, Nickel and nickel alloy welding wires.

GB/T 16253, Pressure-bearing steel castings.

GB/T 16598, Titanium and titanium alloy discs and rings.

GB/T 17791, Seamless copper and copper alloy tubes for air conditioning and refrigerating equipment.

GB/T 18984, Seamless steel tubes for low temperature piping.

GB/T 19189, Quenched and tempered high strength steel plates for pressure vessels.

GB/T 21183, Zirconium and zirconium alloy plates, strips and foils.

GB/T 21832 (all parts), Welded austenitic-ferritic duplex stainless steel pipes.

GB/T 21833 (all parts), Seamless austenitic-ferritic duplex stainless steel pipes.

GB/T 24511, Stainless steel and heat-resisting steel plates and strips for pressure equipment.

GB/T 24593, Welded austenitic stainless steel tubes for boilers and heat exchangers.

GB/T 26283, Zirconium and zirconium alloy seamless tubes.

GB/T 29168.2, Petroleum and natural gas industries - Induction bends, fittings and flanges for pipeline transportation systems - Part 2: Fittings.

GB/T 29168.3, Petroleum and natural gas industries - Induction bends, fittings and flanges for pipeline transportation systems - Part 3: Flanges.

GB/T 30059, Corrosion-resisting alloy seamless tubes for heat exchangers.

GB/T 30568, Zirconium and zirconium alloy forgings.

GB/T 32964, Welded stainless steel pipes for liquefied natural gas.

GB/T 34275, Pressure piping code - Long distance pipeline.

GB/T 38106, Aluminium and aluminium alloy plates for pressure vessels.

GB/T 38512, Aluminium and aluminium alloy tubes for pressure vessels.

GB/T 39255, Shielding gases for welding and cutting.

NB/T 47008, Carbon and alloy steel forgings for pressure equipment.

NB/T 47009, Alloy steel forgings for low temperature pressure equipment.

NB/T 47010, Stainless steel and heat-resisting steel forgings for pressure equipment.

NB/T 47013 (all parts), Nondestructive testing of pressure equipment.

NB/T 47018 (all parts), Technical conditions for ordering welding consumables for pressure equipment.

NB/T 47019.2, Technical conditions for ordering tubes for boilers and heat exchangers - Part 2: Non-alloy steels and alloy steels with specified room temperature properties.

NB/T 47019.3, Technical conditions for ordering tubes for boilers and heat exchangers - Part 3: Non-alloy steels and alloy steels with specified elevated temperature properties.

NB/T 47028, Nickel and nickel alloy forgings for pressure vessels.

NB/T 47029, Aluminium and aluminium alloy forgings for pressure vessels.

NB/T 47046, Nickel and nickel alloy plates for pressure equipment.

NB/T 47047, Nickel and nickel alloy seamless tubes for pressure equipment.

JB/T 10087, Steel castings for pressure-bearing parts of steam turbines - Technical specification.

YS/T 753, Zirconium and zirconium alloy plates for pressure vessels.

3 Terms and definitions

The terms and definitions given in GB/T 3375 and the following ones apply to this document. In case of any inconsistency, the definitions of this document prevail.

3.1 Preliminary welding procedure specification (pWPS): the welding procedure document drawn up in order to carry out the welding procedure qualification.

3.2 Welding procedure qualification: the test process and the evaluation of the results carried out in order to verify the correctness of the welding procedure drawn up for the weldment. In this document, welding procedure qualification means the process of carrying out verification tests on the preliminary welding procedure specification and of evaluating the results, in order to establish whether the mechanical properties, the bending properties and other properties of the welded joint welded according to the pWPS, or the chemical composition, the corrosion resistance and the bending properties of the surfacing layer of the corrosion-resistant surfacing, comply with the specified requirements.

3.3 Procedure qualification record (PQR): the report which records the verification tests and their examination results and which evaluates the preliminary welding procedure specification drawn up.

3.4 Welding procedure specification (WPS): the welding procedure document compiled on the basis of a qualified welding procedure qualification report and used to give instructions for the welding of the product.

3.5 Welding working instruction (WWI): the detailed document relating to the machining and the operations involved in manufacturing the weldment. The working instruction used during production welding ensures the reproducibility of the quality of the work.

3.6 Weldment: the pressure equipment, or a part of it, joined by welding processes or provided with a surfacing layer. The weldment consists of two parts, the base metal and the welded joint or the surfacing layer.

3.7 Test coupon: the weldment welded according to the predetermined welding procedure and used for the welding tests. The test coupon consists of two parts, the base metal and the welded joint or the surfacing layer.

3.8 Mixed flux: two fluxes of different designations mixed together in a given proportion and used in that form; such a flux is called a mixed flux.

3.9 Post weld heat treatment (PWHT): the thermal process able to modify the structure and the properties of the welded joint and the welding residual stresses.

3.10 Lower transformation temperature: the phase transformation temperature at which austenite starts to form during heating.

3.11 Upper transformation temperature: the phase transformation temperature at which the transformation into austenite is completed during heating.

3.12 Face bend: the bending in which the surface of the bend specimen subjected to tension is the face side of the weld. The side showing the larger weld width is the face side; when the weld widths of the two sides are equal, the side on which the cover pass was completed first is the face side.

3.13 Root bend: the bending in which the surface of the bend specimen subjected to tension is the root side of the weld.

3.14 Side bend: the bending in which the surface of the bend specimen subjected to tension is the transverse section of the welded joint.

3.15 Electrogas welding: an arc welding process in which, in the vertical position, the arc between the continuously fed welding wire and the weld pool produces the joining, and in which copper shoes and moulds force the molten weld metal to take shape. Solid wire, metal-cored wire or flux-cored wire may be used, with a single shielding gas or a mixed shielding gas; self-shielded flux-cored wire does not require an additional shielding gas.

3.16 Stud arc welding: a welding process in which the end of a metal stud, or of a similar part, and the surface of the workpiece are melted under the action of an electric arc and an external pressure, so that the two molten parts fuse together. No filler metal is used during welding; a shielding gas or a flux may or may not be used.

3.17 Supplemental filler metal: cut welding wire, solid welding wire, metal powder, composite metal material and similar products which are melted into the weld in addition to the melted electrode.

3.18 Imperfection: any discontinuity, incompleteness, unsoundness, non-uniformity and the like.

3.19 Weld imperfection: a general designation of the discontinuities, the non-uniformities, the lack of tightness and other poor joining defects of the structure and the constitution of a welded joint.

3.20 Welding defect: a weld imperfection exceeding the specified limit.

3.21 Heat input of strip surfacing welding: the heat input by the welding heat source onto a unit area of the surfacing metal during strip surfacing welding. It is calculated, in joules per square millimetre, as sixty multiplied by the current I multiplied by the voltage U, divided by the product of the travel speed V and the strip width.

3.22 Buttering: the surfacing, before the final welding of the joint preparation, of added material on one or on both groove faces of the joint, in order to provide a suitable transition layer of deposited weld metal for the subsequent welding.

4 General requirements

4.1 In addition to complying with the provisions of this document, the welding procedure qualification of pressure equipment shall also comply with the requirements of the relevant standards and of the technical documents of boiler, pressure vessel and pressure piping products.

4.2 The general process of welding procedure qualification is the following: according to the weldability of the metallic material and of the welding consumables, and in accordance with the provisions of the design documents and with the manufacturing process, a preliminary welding procedure specification is drawn up, the test coupon is prepared, the test specimens are made, it is examined whether the welded joint or the corrosion-resistant surfacing layer complies with the specified requirements, and a welding procedure qualification report is formed in order to evaluate the pWPS.

4.3 Welding procedure qualification shall be carried out within the organization itself. The equipment and the instruments used for the welding procedure qualification shall be in a normal working condition, the metallic materials and the welding consumables shall comply with the relevant standards, and the test coupons shall be welded by welders skilled in the operation and using the equipment of the organization itself.

4.4 A qualified welding procedure means the welding procedure factors listed in a qualified welding procedure qualification report, namely the general welding procedure qualification factors, the essential factors and the supplementary factors among the dedicated welding procedure qualification factors of butt welds and fillet welds, and the factors requiring requalification among the welding procedure qualification factors of corrosion-resistant surfacing.

4.5 The flow chart of the welding procedure specification is given in Annex A.

5 Welding procedure qualification factors and classification

5.1 General welding procedure qualification factors of the various welding processes and their classification.

5.1.1 Welding processes and their classification. The welding processes are classified as follows: gas welding, shielded metal arc welding, submerged arc welding, tungsten inert gas arc welding, gas metal arc welding including flux-cored wire arc welding, electroslag welding, plasma arc welding, friction welding, electrogas welding, stud arc welding and electron beam welding.

5.1.2 Metallic materials and their classification. On the basis of the chemical composition, the mechanical properties and the weldability, the base metals used for welded pressure equipment are classified and grouped according to Table 1. The supplementary provisions on the classification and the grouping of base metals not listed in Table 1 are given in Annex B.

Table 1, Classification and grouping of the base metals used for welded pressure equipment, gives for each class and group the steel number, grade, level or designation, together with the standard covering that material.

Class Fe-1, group Fe-1-1 includes the grades 10, 15, 20, 20G, Q195, Q215A, Q215B, Q235AF, Q235A, Q235B, Q235C, Q235D, Q245R, Q275A, Q275B, 10MnDG, 20MnG, L175/A25, L175P/A25P, L210/A, L245/B, L245N/BN, L245R/BR, L245Q/BQ, L245M/BM, L290, L290N, L290Q, L290M, F290, WCA, ZG 200-400, CF370, CF415, CF415K, LF415K1 and LF415K2, covered by GB/T 699, GB/T 700, GB/T 711, GB/T 713, GB/T 3087, GB/T 3091, GB/T 3274, GB/T 5310, GB/T 6479, GB/T 8163, GB/T 9711, GB/T 9948, GB/T 11352, GB/T 12229, GB/T 13237, GB/T 13401, GB/T 18984, GB/T 29168.2, GB/T 29168.3, GB/T 34275, NB/T 47008 and NB/T 47019.2.

Class Fe-1, group Fe-1-2 includes the grades 25, Q345R, Q345A, Q345B, Q345C, Q345D, Q345E, GB/SA 516 Gr70, GB/SA 537 Cl1, Q355B, Q355C, Q355D, 09MnD, 16Mn, 25MnG, 16MnD, 16MnDR, 16MnDG, 15MnNiDR, 09Mn2VDG, 09MnNiDR, 09MnNiD, Q390A, Q390B, Q390C, Q390D, Q390E, L320, L320N, L320Q, L320M, L360, L360N, L360Q, L360M, L390, L390N, L390Q, L390M, CF485, CF485K, LF485K2, ZG 230-450, ZG18, WCB, WCC, A105 and F360, covered by GB/T 150.2, GB/T 699, GB/T 713, GB/T 1591, GB/T 3091, GB/T 3531, GB/T 5310, GB/T 6479, GB/T 8163, GB/T 9711, GB/T 11352, GB/T 12228, GB/T 12229, GB/T 13401, GB/T 16253, GB/T 18984, GB/T 29168.2, GB/T 29168.3, GB/T 34275, NB/T 47008, NB/T 47009 and NB/T 47019.2.

Class Fe-1, group Fe-1-3 includes the grades Q370R, 15MnNiNbDR, Q420R, Q420A, Q420B, Q420C, Q420D, Q420E, Q460C, Q460D, Q460E, L415, L415M, L415N, L415Q, L450, L450M, L450Q, L485, L485M, L485Q, F415, F450 and F485, covered by GB/T 713, GB/T 1591, GB/T 3531, GB/T 8163, GB/T 9711, GB/T 29168.2, GB/T 29168.3 and GB/T 34275.

Class Fe-1, group Fe-1-4 includes the grades 07MnMoVR, 07MnNiVDR, 07MnNiMoDR, 12MnNiVR, 08MnNiMoVD, 10Ni3MoVD, L555, L555M, L555Q and F555, covered by GB/T 19189, GB/T 9711, GB/T 29168.2, GB/T 29168.3, GB/T 34275 and NB/T 47009.

Class Fe-2 has no group number and no base metal grade listed in Table 1.

Class Fe-3, group Fe-3-1 includes the grades 15MoG, 20MoG, 12CrMo and 12CrMoG, covered by GB/T 5310, GB/T 6479, GB/T 9948, NB/T 47008 and NB/T 47019.2.

Class Fe-3, group Fe-3-2 includes the grades 20MnMo, 20MnMoD, 10MoWVNb and 12SiMoVNb, covered by NB/T 47008, NB/T 47009, GB/T 6479 and GB/T 13401.

Class Fe-3, group Fe-3-3 includes the grades 13MnNiMoR, 18MnMoNbR, 20MnNiMo, 20MnMoNb, 15NiCuMoNb and 15Ni1MnMoNbCu, covered by GB/T 713, NB/T 47008 and GB/T 5310.

Class Fe-4, group Fe-4-1 includes the grades 09CrCuSb, 12Cr1Mo, 14Cr1Mo, 14Cr1MoR, 15CrMo, 15CrMoG, 15CrMoR, GB/SA 387 Gr12 Cl2, ZG 18CrMo, ZG 20CrMo, AF11, AF11G, AF12 and AF12G, covered by GB/T 150.2, GB/T 713, GB/T 3077, GB/T 5310, GB/T 6479, GB/T 9948, GB/T 13401, GB/T 16253, JB/T 9625, JB/T 10087, NB/T 47008, NB/T 47019.2 and NB/T 47019.3.

Class Fe-4, group Fe-4-2 includes the grades 12Cr1MoV, 12Cr1MoVG, 12Cr1MoVR, AF14, ZG 15Cr1Mo1V and ZG 20CrMoV, covered by GB/T 713, GB/T 3077, GB/T 5310, GB/T 9948, GB/T 13401, JB/T 9625, JB/T 10087, NB/T 47008 and NB/T 47019.3.

Class Fe-5A, without group subdivision, includes the grades 08Cr2AlMo, 07Cr2AlMoR, 12Cr2Mo, 12Cr2MoG, 12Cr2Mo1, 12Cr2Mo1R, 07Cr2MoW2VNbB, AF22, AF22G and ZG 17Cr2Mo, covered by GB/T 150.2, GB/T 713, GB/T 5310, GB/T 6479, GB/T 9948, GB/T 13401, GB/T 16253, NB/T 47008, NB/T 47019.2 and NB/T 47019.3.

Class Fe-5B, group Fe-5B-1 includes the grades 12Cr5Mo, 12Cr5MoI, 12Cr5MoNT, AF5, AF5G and ZG 16Cr5Mo, covered by GB/T 6479, GB/T 9948, GB/T 13401, GB/T 16253, NB/T 47008 and NB/T 47019.2.

Class Fe-5B, group Fe-5B-2 includes the grades 10Cr9Mo1VNbN, 10Cr9MoW2VNbBN, 10Cr11MoW2VNbCu1BN, 11Cr9Mo1W1VNbBN and AF91, covered by GB/T 5310, GB/T 13401, NB/T 47008, NB/T 47019.2 and NB/T 47019.3.

Class Fe-5B, group Fe-5B-3 includes the grades 12Cr9MoI, 12Cr9MoNT, AF9 and AF9G, covered by GB/T 9948, GB/T 13401 and NB/T 47019.2.

Class Fe-5C, without group subdivision, includes the grades 12Cr2MoWVTiB, 12Cr3MoVSiTiB, 12Cr2Mo1VR, 12Cr2Mo1V and 12Cr3Mo1V, covered by GB/T 5310, GB/T 713 and NB/T 47008.

Class Fe-6, without group subdivision, includes the grades S41008 (06Cr13), S41010 (12Cr13) and S42020 (20Cr13), covered by GB/T 3280, GB/T 13296 and GB/T 14976.

Class Fe-7, group Fe-7-1 includes the grades S11306 (06Cr13) and S11348 (06Cr13Al), covered by GB/T 24511 and NB/T 47010.

Class Fe-7, group Fe-7-2 includes the grades S11710 (10Cr17) and S11972 (019Cr19Mo2NbTi), covered by GB/T 3280, GB/T 13296, GB/T 14976 and GB/T 24511.

Class Fe-8, group Fe-8-1 includes the austenitic stainless steel grades S30210 (12Cr18Ni9), S30403 (022Cr19Ni10), S30408 (06Cr19Ni10), S30409 (07Cr19Ni10), S30432 (10Cr18Ni9NbCu3BN), S30453 (022Cr19Ni10N), S30458 (06Cr19Ni10N), S30478 (06Cr19Ni9NbN), S31252 (015Cr20Ni18Mo6CuN), S31603 (022Cr17Ni12Mo2) and S31608 (06Cr17Ni12Mo2), covered by GB/T 3280, GB/T 4237, GB/T 5310, GB/T 9948, GB/T 12771, GB/T 13296, GB/T 13401, GB/T 14976, GB/T 24511, GB/T 24593, GB/T 32964 and NB/T 47010.