Tiêu chuẩn iso 12633 1 2011

Reference number ISO 12633 1 2011(E) © ISO 2011 INTERNATIONAL STANDARD ISO 12633 1 First edition 2011 09 15 Hot finished structural hollow sections of non alloy and fine grain steels — Part 1 Technica[.]

Classification

Within the non-alloy steel grades listed in Annex A, three qualities—JR, J0, and J2—are defined, each varying in impact toughness, deoxidation methods, and elemental content limits, particularly for sulfur and phosphorus; additionally, these grades differ in inspection and testing requirements to ensure quality and performance standards.

Within the steel grades of fine grain steels listed in Annex B, two qualities—N and NL—are specified, differing primarily in their carbon, sulfur, and phosphorus content, as well as their low-temperature impact properties.

Copyright International Organization for Standardization

Designations

4.2.1 For non-alloy steel structural hollow sections, the steel designation consists of:

 a reference to this part of ISO 12633, i.e ISO 12633-1:2011;

 the capital letter S for structural steel;

 the indication of the minimum specified yield strength for thicknesses  16 mm, expressed in newtons per square millimetre (N/mm 2 );

 the capital letters JR for the qualities with specified impact properties at room temperature;

 the capital letter J and a number 0 or 2 for the qualities with specified impact properties at 0 °C and

 the capital letter H to indicate hollow sections

4.2.2 For fine grain steel structural hollow sections, the steel designation consists of:

 a reference to this part of ISO 12633, i.e ISO 12633-1:2011;

 the capital letter S for structural steel;

 the indication of the minimum specified yield strength for thicknesses  16 mm, expressed in newtons per square millimetre (N/mm 2 );

 the capital letter N to indicate normalized or normalized rolled (see 6.4);

 the capital letter L for the qualities with specified minimum values of impact energy at a temperature of

 the capital letter H to indicate hollow sections

4.2.3 For modification of the designations in case of special delivery conditions, see 6.4

4.2.4 The steel shall be designated as illustrated by the following examples:

NOTE Steel names used in this part of ISO 12633 differ from those in ISO/TS 4949

5 Information to be supplied by the purchaser

Mandatory information

When making an enquiry or placing an order, the purchaser must provide essential information including the required quantity (mass, total length, or number), the specific type and length range in accordance with ISO 12633-2, and detailed specifications of the product form to ensure accurate processing and fulfillment.

HFCHS = hot-finished circular hollow sections;

HFRHS refers to hot-finished square or rectangular hollow sections, which are specified by their steel designation according to section 4.2 The dimensions of these sections are detailed in ISO 12633-2, ensuring precise sizing for construction and engineering purposes When requesting HFRHS, it is essential to specify the required options outlined in section 5.2 to meet project specifications Additionally, the type of inspection document required, as described in section 7.2 and Tables 2 and 3, must be determined to ensure quality assurance and compliance with standards.

Options

ISO 12633 specifies several options that can be selected according to the purchaser's requirements, listed with corresponding clause references for clarity If the purchaser does not specify any options at the time of enquiry or order, products will be supplied according to the basic specifications outlined in clause 5.1 These options include: Option 1, which involves conducting a product analysis (see 6.5.1); Option 2, providing a maximum carbon equivalent value (CEV) for non-alloy grades as per Table A.2 (see 6.5.2); Option 3, reporting cast analysis contents of elements like Cr, Cu, Mo, Ni, Ti, and V on inspection certificates for non-alloy grades (see 6.5.2); and Option 4, supplying a maximum carbon equivalent value for fine grain steels S275 and S355 according to Table B.2 (see 6.5.3).

The material must comply with a Mo + Cr content of ≤ 0.30% Impact properties of quality J0 and JR should be verified through testing when specified, particularly for products with detailed inspection requirements The material must be suitable for hot-dipped galvanized coating to ensure corrosion resistance Weld repairs on non-alloy structural steel hollow sections are not permitted, maintaining structural integrity Additionally, specific inspection and testing procedures are required for non-alloy grades of quality JR and J0 to ensure compliance with standards.

Example

General

Structural hollow sections of non-alloy steels shall comply with the requirements of Annex A; structural hollow sections of fine grain steels shall comply with the requirements of Annex B.

Steel manufacturing process

6.2.1 The steel manufacturing process shall be at the discretion of the steel producer

6.2.2 For the non-alloy structural steels given in Annex A, the method of deoxidation shall be as given in Table A.1

6.2.3 For the fine grain steels given in Annex B, the method of deoxidation shall be as given in Table B.1

6.2.4 The fine grain steels given in Annex B shall have a ferritic grain size equal to or finer than 6 when measured in accordance with ISO 643

Structural hollow section manufacturing process

6.3.1 Structural hollow sections shall be manufactured by a seamless or by a welding process Welded sections manufactured by a continuous process shall not include welds used for joining lengths of the flat rolled-strip prior to forming the hollow section, except as permitted in 9.4.3

6.3.2 Electric welded hollow sections are normally supplied without trimming the internal weld bead

6.3.3 For quality assurance requirements, see ISO 404 If the purchaser specifies quality assurance, an appropriate International Standard, such as ISO 9001, can be used.

Delivery conditions

6.4.1 The hollow sections shall be delivered in the following conditions:

 qualities JR, J0 and J2: hot-finished;

 qualities N and NL: normalized (normalized includes normalized rolled)

6.4.2 It may be necessary for seamless hollow sections with a wall thickness above 16 mm or when T/D is greater than 0,15 to apply accelerated cooling after austenitizing to achieve the intended structure or liquid quenching and tempering to achieve the mechanical properties The decision shall be left to the discretion of the manufacturer, but shall be stated to the purchaser at the time of enquiry and order Hollow sections treated in such a way shall be designated in the following ways: a) for accelerated cooling: by the steel name supplemented by the symbol “+DC”; b) for quenching and tempering:

1) by the steel name supplemented by the symbol “+QT” in the case of non-alloy steels;

2) by a modified steel name for which the letter N is replaced with Q in cases of fine grain steels, e.g

Details of the special delivery conditions shall be given in the inspection document and the product shall be marked in accordance with the above-mentioned stipulations

Cold-formed hollow sections that undergo subsequent heat treatment to achieve metallurgical conditions equivalent to those obtained by normalizing rolling are considered compliant with the requirements of ISO 12633.

Chemical composition

6.5.1 The cast analysis reported by the steel producer shall apply and shall comply with the requirements of

Option 1 (see 5.2): a product analysis shall be carried out for hollow sections supplied with specific inspection and testing

The permissible deviations of the product analysis from the specified-limits cast analysis are given in Table 1

Table 1 — Permissible deviations of the product analysis from the specified limits of the cast analysis

Permissible maximum content in the cast analysis

Permissible deviation of the product analysis from specified limits for the cast analysis mass fraction

Mn non-alloy  1,60 +0,10 fine grain  1,70 0,05

For S235JRH steel with thicknesses up to 16 mm, the allowable deviation in aluminum total is greater than or equal to 0.020 minus 0.005 a, with permissible deviations of 0.04% C For thicknesses exceeding 16 mm and up to 40 mm, the permissible deviation increases to 0.05% C, ensuring compliance across different material thicknesses.

When a CEV is required it shall be determined from the cast analysis using the formula:

Mn Cr Mo V Ni Cu

6.5.2 For non-alloy steel products, the following additional requirements may be requested at the time of enquiry and order for products supplied with specific inspection and testing (see 7.1)

Option 2 (see 5.2): the CEV in accordance with Table A.2

Option 3 (see 5.2): the recording on the inspection certificate or inspection report of the Cr, Cu, Mo, Ni, Ti and

6.5.3 For fine grain steel hollow sections, the following additional requirements may be requested at the time of enquiry and order

Option 4 (see 5.2): the CEV for steel grades S275 and S355 in accordance with Table B.2

Option 5 (see 5.2): for steel grade S460, the following limits for the cast analysis:

V + Nb + Ti  0,22 % and Mo + Cr  0,30 %

A maximum CEV may be agreed between the purchaser and manufacturer as an alternative to option 5.

Mechanical properties

6.6.1 Under the inspection and testing conditions as specified in Clause 7 and in the delivery condition as specified in 6.4, the mechanical properties shall comply with the relevant requirements of Tables A.3 and B.3

Stress relief annealing above 580°C orlasting longer than 1 hour can cause deterioration of mechanical properties For higher temperature or extended duration annealing, it is essential to agree on the minimum mechanical property values during the inquiry and ordering process to ensure product performance.

For impact testing, standard V-notch test pieces as specified in ISO 148-1 must be used When the nominal product thickness is insufficient to prepare standard test specimens, smaller test pieces with widths between 5 mm and 10 mm may be utilized The minimum average impact values listed in Tables A.3 and B.3 should be proportionally adjusted based on the actual width of the test specimen relative to the standard size.

Impact tests are not required for nominal thickness less than 6 mm

For fine grain steel hollow sections with thicknesses that prevent the extraction of impact test specimens wider than 5 mm, the ferritic grain size must be verified using the method outlined in ISO 643.

To ensure proper grain refining with aluminium, the cast analysis must show an aluminium content of at least 0.020% total aluminium or 0.015% acid-soluble aluminium When these thresholds are met, verification of grain size is not necessary, indicating that the grain size requirement is considered fulfilled.

The impact properties of structural hollow sections made from steel qualities J2, N, and NL must be verified in accordance with section 6.6.4(a) However, the impact properties of hollow sections constructed from steel qualities JR and J0 are not subject to verification, as specified in section 6.6.4(b).

Option 6 (see 5.2): the purchaser may request at the time of enquiry and order, for products supplied with specific inspection and testing (see option 9), that the impact properties be verified.

Technological properties

The steels specified in this part of ISO 12633 shall be suitable for welding by all appropriate welding processes

As product thickness, strength level, and carbon equivalent level increase, the risk of cold cracking in the welded zone becomes more significant Cold cracking primarily occurs due to a combination of factors, including high residual stresses, low weld metal ductility, and improper welding parameters, which are exacerbated by higher material thickness and carbon content Managing these factors is essential to prevent cold cracking and ensure the integrity of the welds.

 the amount of diffusible hydrogen in the weld metal;

 a brittle structure of the heat affected zone;

 significant tensile stress concentrations in the welded joint

When following recommendations outlined in relevant standards, the appropriate welding conditions and ranges for different steel grades can be determined based on factors such as product thickness, welding energy applied, design requirements, electrode efficiency, welding process, and weld metal properties.

Option 7 (see 5.2): at the time of enquiry and order, the purchaser may request that the products be suitable for hot dip galvanized coating.

Surface condition

Hollow sections must have a smooth surface that reflects their manufacturing method, with permissible bumps, cavities, or shallow longitudinal grooves These surface imperfections are acceptable as long as the remaining thickness remains within specified tolerances, ensuring quality and durability.

Manufacturers can remove surface defects through grinding, provided the hollow section's remaining thickness after repair does not fall below the minimum permissible limit (Refer to ISO 12633-2 for details on thickness tolerances.)

6.8.2 The ends of the hollow section shall be cut nominally square with the axis of the product

6.8.3 For both non-alloy and fine grain structural steel hollow sections manufactured by a welded process, repair of the weld shall be permitted

Welding repairs are permitted for non-alloy structural steel hollow sections made through seamless or welding processes, unless specified otherwise The specific conditions and extent of such repairs must be mutually agreed upon by the manufacturer and the purchaser, ensuring quality and compliance This guideline ensures proper maintenance standards for steel hollow sections in structural applications.

Option 8 (see 5.2): the purchaser may specify at the time of enquiry and order that repair of the body by welding shall not be carried out

For fine grain structural steel hollow sections manufactured by either a seamless or welded process, repair of the body by welding shall not be permitted unless otherwise agreed

Welding repairs must be performed by operators qualified according to ISO 9606-1 standards All repair procedures should comply with ISO 15607, ISO 15609-1, and ISO 15614-1 to ensure quality and consistency Additionally, repair welding procedures must be documented within the manufacturer's quality assurance system to maintain standards and traceability.

6.8.6 The repaired hollow section shall comply with all the requirements of this part of ISO 12633.

Non-destructive testing of welds

The seam weld of all welded hollow sections supplied with specific inspection and testing shall be subjected to a non-destructive test (NDT) (see 9.4).

Tolerances and mass

Tolerances for hot-finished structural hollow sections shall be as specified in ISO 12633-2

Mass shall be determined using a density of 7,85 kg/dm 3

ISO 12633-2 provides comprehensive dimensions, sectional properties, and mass per unit length for a variety of standard sizes of hot-finished structural hollow sections It is recommended that purchasers choose hollow section dimensions from this standardized range to ensure quality and consistency Adhering to these standard sizes facilitates optimal structural performance and simplifies procurement processes Selecting from ISO 12633-2 specifications helps ensure compliance with international standards and enhances the reliability of the construction.

Types of inspection and testing

Hollow sections made of non-alloy steels in qualities JR and J0 (see Annex A) are to undergo non-specific inspection and testing according to ISO 404 standards, unless the purchaser specifies otherwise at the time of enquiry or order.

Option 9 (see 5.2): the purchaser may request specific inspection and testing at the time of enquiry and order

7.1.2 Hollow sections of non-alloy steel quality J2 (see Annex A) and fine grain steels of qualities N and NL

(see Annex B) shall be subjected to specific inspection and testing in accordance with ISO 404.

Types of inspection documentation

7.2.1 For products supplied with non-specific inspection and testing, a test report (see ISO 10474:1991,

2.2) in accordance with ISO 10474 shall be provided

The test report shall contain the following information: a) commercial transactions and parties involved; b) description of products to which the test report applies; c) information on tests as follows:

2) chemical composition: a cast analysis; d) authentication

7.2.2 For products supplied with specific inspection and testing, an inspection certificate (i.e type “3.1.A”,

“3.1.B” or “3.1.C” as specified in ISO 10474:1991, 3.1,) or an inspection report (“3.2” as specified in

ISO 10474:1991, 3.2) in accordance with ISO 10474, shall be provided

The purchaser shall indicate in the enquiry and order the type of inspection document required [see 5.1 g)]

When inspection documents such as 3.1.A, 3.1.C, or 3.2 are specified, the purchaser must notify the manufacturer of the designated inspection organization's or individual's address, ensuring they produce the necessary inspection document.

In the case of the inspection report 3.2, it shall be agreed which party is to issue the certificate

An inspection certificate or report must include essential details such as the involved parties and commercial transactions, a comprehensive description of the products covered by the inspection, and detailed information about the conducted tests to ensure transparency and compliance.

1) tensile test: test piece shape and test results;

2) impact test: test piece type and test results;

3) the cast analysis and, if applicable, the product analysis; d) authentication

Inspection and testing

The requirements for inspection and testing are given in Table 2 for hollow sections of non-alloy steels and in Table 3 for hollow sections of fine grain steels

7.3.2 Non-specific inspection and testing

When products are supplied without specific inspection and testing, the manufacturer must conduct tests according to their established procedures to ensure that all products produced using the same manufacturing process meet the order requirements These tests verify product conformity and quality, even if the tested samples are not the exact items supplied This process guarantees consistent quality across all produced units, maintaining compliance with order specifications.

Products must undergo specific inspection and testing before supply Tests should be conducted on the final products, test units incorporating the product, or, where applicable, on all hollow sections Ensuring thorough inspection is essential for quality assurance and compliance with standards.

Table 2 — Inspection and test programme for non-alloy steel hollow sections

Inspection and test requirements Scope of inspection and test programme and type of document

Non-specific inspection and testing Specific inspection and testing

Inspection certificate (type 3.1.A, 3.1.B or 3.1.C) b Inspection report (type 3.2) b

One result per delivery item One per cast

One result per delivery item One per test unit de

Mandatory requirements 3 Impact test quality J2 only

6.6 9.2 Not applicable One per test unit de

9.4 Not applicable All products, full length

9.1 Not applicable One per test unit

Optional requirements 7 Cast analysis additional elements

The article references ISO 10474:1991 standards, indicating that testing procedures are aligned with these guidelines It specifies that a test unit is typically not applicable unless option 6 is requested, with one test per unit Different sampling methods, including longitudinal or transverse samples, are applied at the manufacturer’s discretion Additional details regarding test units and procedures can be found in sections 2.2, 3.1, 3.2, and 8.1.3 of the standard, ensuring clarity and compliance in testing protocols.

Table 3 — Inspection and test programme for fine grain steel hollow sections

Inspection and test requirements Scope of inspection and test programme and type of document

Specific inspection and testing Inspection certificate (3.1.A, 3.1.B or 3.1.C) a

9.2 One per test unit cd

9.1 One per test unit c a In accordance with ISO 10474:1991, 3.1 b In accordance with ISO 10474:1991, 3.2 c For test unit, see 8.1.3 d Longitudinal or transverse samples at discretion of the manufacturer

Frequency of tests

8.1.1 For products supplied with non-specific inspection and testing, see 7.3.2

For products supplied with specific inspection and testing requirements, the verification of mechanical properties and product analysis must be conducted by the designated test unit A test unit consists of a batch of hollow sections from the same grade and dimensions, produced by the same manufacturing process (such as electric welding or submerged arc welding), and, if applicable, in the same heat treatment condition, all submitted for acceptance simultaneously.

From each test unit one sample shall be taken sufficient for the preparation of the following test pieces:

 two sets of three impact test pieces;

 one product analysis when required

8.1.3 The test unit shall consist of the tonnage of sections as specified in Table 4

Type of section Test unit

Outside diameter External perimeter Mass

Preparation of samples and test pieces

8.2.1 Selection and preparation of samples for chemical analysis

Samples for product analysis should be taken from test pieces or mechanical testing samples, ensuring they represent the entire thickness of the hollow section at the same location as the mechanical test samples Sample preparation must comply with ISO 14284 standards to ensure accurate and consistent analysis.

8.2.2 Location and orientation of samples for mechanical tests

Tensile test specimens must meet specific requirements based on the section shape; for circular, rectangular, or square sections, the entire specimen may be used, while for circular sections not tested in full, specimens should be extracted longitudinally from a point away from the weld, ensuring accurate and representative test results (see Annex C).

Manufacturers may, at their discretion, choose to take transverse test pieces for quality assessment For square or rectangular sections that are not tested in their full cross-section, test samples should be extracted longitudinally, positioned midway between the corners from one side that does not contain a weld, as detailed in Annex C.

Alternatively, at the discretion of the manufacturer, transverse test pieces may be taken

Impact testing requires test pieces to meet specific criteria: for circular sections, samples must be extracted longitudinally at a point distant from the weld, ensuring accurate assessment of material toughness (see Annex C).

Manufacturers may, at their discretion, select transverse test pieces for evaluation For square or rectangular sections, test samples should be taken longitudinally, positioned midway between the corners on a side without a weld, as detailed in Annex C.

Alternatively, at the discretion of the manufacturer, transverse test pieces may be taken

8.2.3 Preparation of test pieces for mechanical tests

The requirements of ISO 377 shall apply in conjunction with the test piece location specified in 8.2.2

The requirements of ISO 6892-1 and ISO 6892-2, as appropriate, shall apply

Test pieces may be non-proportional but in cases of dispute proportional test pieces having a gauge length o 5,65

Impact V-notch test pieces must be machined and prepared according to ISO 148-1 standards For nominal thicknesses greater than 12 mm, standard test pieces should be machined to ensure that one side remains within 2 mm of a rolled surface For nominal thicknesses of 12 mm or less, especially when using test pieces with reduced sections, the width requirements must be met to ensure proper testing conditions.

The size of the NOTE test piece depends on the actual thickness of the sample, ensuring accurate testing conditions For circular hollow sections, additional allowances must be considered to account for the curvature of the section, which can affect test results Properly sizing the test specimen based on these factors is essential for reliable and consistent testing outcomes.

Chemical analysis

The elements to be determined and reported shall be those given in Table A.1, unless option 3 is requested (see 5.2) or in Table B.1

The choice of a suitable physical or chemical analytical method for the analysis shall be at the discretion of the manufacturer

In case of dispute, the method used shall be agreed taking into account the relevant existing International Standards.

Mechanical tests

Tensile tests must be conducted within a temperature range of 10 °C to 35 °C to ensure accurate material performance assessment Impact tests should be performed at specific temperatures outlined in Table A.3 for non-alloy steels and Table B.3 for fine grain steels, ensuring compliance with industry standards.

The tensile test shall be carried out in accordance with ISO 6892-1 and ISO 6892-2

For the specified yield strength in Tables A.3 and B.3, the upper yield strength (R eH ) shall be determined

If a yield phenomenon is not present, the 0,2 % proof strength (R p0,2 ) or the 0,5 % proof stress total elongation (R t0,5 ) shall be determined In cases of dispute, the 0,2 % proof strength (R p0,2 ) shall apply

If a non-proportional test piece is used, the percentage elongation value obtained shall be converted to the value for a gauge length L o 5,65 S o using the conversion tables given in ISO 2566-1

The impact test must be conducted according to ISO 148-1 and evaluated following ISO 404 standards The test results are considered acceptable if the average of three test specimens meets the specified requirement, allowing one individual value to fall below the requirement as long as it is not less than 70% of that value If these conditions are not met, a second set of three test specimens must be tested from the same sample The test unit is deemed compliant only if, after testing the second set, the average and individual values satisfy the specified criteria simultaneously.

1) the average value of six tests shall be equal to or greater than the specified value;

2) not more than two of six individual values may be lower than the specified value;

3) not more than one of the six individual values may be lower than 70 % of the specified value; c) if these conditions are not satisfied, the sample product is deemed not to comply with this part of ISO 12633 and retests may be carried out on the remainder of the test unit (see 9.5).

Visual examination and dimensional inspection

The hollow sections shall be visually examined for compliance with the requirements of 6.8

The dimensions of the hollow sections shall be inspected for compliance with the requirements of ISO 12633-2.

Non-destructive testing

For nondestructive testing (NDT) of welded structural hollow sections, the inspection method must adhere to clauses 9.4.2 or 9.4.3 NDT can be performed either on the circular shape before final forming or on the round, square, or rectangular hollow sections after they have been fully formed, based on the manufacturer's discretion.

Weld seams must be tested according to international standards, specifically ISO 10893-2 to acceptance level E5, excluding the use of the rotating tube/pancake coil technique Alternatively, testing can be conducted in accordance with ISO 10893-3 or ISO 10893-11, with acceptance criteria based on the specified standards.

N 15 internal/external notches and that for the application of ISO 10893-3 a notch width of not greater than twice the depth of the reference notch with a maximum of 1,0 mm shall apply

The International Standard to be applied is at the discretion of the manufacturer

The weld seam shall be tested to level U5 in accordance with ISO 10893-11 or by radiography in accordance with ISO 10893-6 with an image quality class B

Butt welds used to join strip or plate sections in the helically submerged arc welding process are permitted, provided they undergo the same testing procedures and meet the same acceptance criteria as the primary weld seam.

Retests, sorting and reprocessing

For retests, sorting and reprocessing, ISO 404 shall apply

Each hollow section must be clearly marked using durable methods such as painting, stamping, adhesive labels, or attached tags, except where provisions in section 10.2 for bundled hollow sections apply Proper marking ensures identification, compliance, and safety in structural applications.

 the abridged designation, e.g ISO 12633-1 - S275J0 ( but see also 6.4 for special delivery conditions);

 the manufacturer's name or trademark;

 in the case of specific inspection and testing, an identification number, e.g order item number, which permits the correlation of the product or delivery unit to the related inspection document

ISO 12633-1 - S235JR + trademark ISO 12633-1 - S275NL + manufacturer's name + order item number

10.2 Where the products are supplied bundled, the marking required in 10.1 may be on a label, which shall be securely attached to the bundle

Structural hollow sections of non-alloy steels — Chemical composition and mechanical properties

Table A.1 — Chemical composition — Cast analysis for product thickness less than or equal to 65 mm

Steel grade Type of deoxidation a

 40  40,  65 max max max max max bc

S355J2H FF 0,22 0,22 0,55 1,60 0,035 0,035 — a The deoxidation methods are designated as follows:

FN: Rimming steel not permitted;

FF: Fully killed steel containing nitrogen-binding elements in amounts sufficient to bind available nitrogen (e.g min 0,020 % total

The permissible aluminum content is 0.015%, with allowances for slight increases; however, for each 0.001% increase in nitrogen (N), the maximum phosphorus (P) content must be reduced by 0.005%, and the nitrogen content in the cast analysis must not exceed 0.012% The maximum nitrogen limit does not apply if the chemical composition contains at least 0.020% total aluminum (Al) with a minimum Al/N ratio of 2:1, or if sufficient nitrogen-binding elements are present, which should be specified in the inspection document.

Table A.2 — Maximum carbon equivalent value based on cast analysis

Table A.3 — Mechanical properties for non-alloy structural steel hollow sections

Minimum average absorbed energy for standard test pieces b

Impact properties for S355J2H-20 27 are verified only when specified during inquiry and order for products supplied with particular inspection and testing procedures Additionally, impact properties for reduced section test pieces can be found in section 6.6.2.

Structural hollow sections of fine grain steels — Chemical composition and mechanical properties

Table B.1 — Chemical composition — Cast analysis for product thickness less than or equal to 65 mm

S460NLH 0,030 0,025 a The deoxidation method is designated as follows:

A GF steel is fully killed and contains nitrogen-binding elements in sufficient quantities to effectively bind available nitrogen, resulting in a fine grain structure When adequate nitrogen-binding elements are present, the minimum total aluminum content is not applicable Additionally, if the copper content exceeds 0.30%, the nickel content must be at least half of the copper content, ensuring alloy quality and performance.

Table B.2 — Maximum carbon equivalent value based on cast analysis

Steel grade Type of deoxidation

Nominal thickness mm Nominal thickness mm °C

Minimum average absorbed energy for standard test pieces a

S460NLH 50 27 a For impact properties for reduced section test pieces, see 6.6.2

Location of samples and test pieces for hollow sections

This annex gives information on the location of samples and test pieces for hollow sections (see 8.2.2)

C.1.2 Location of samples for tensile test

For circular, rectangular or square sections, the test piece may be the full section of the product

Figure C.1 — Small sections location of samples a At any point on circumference, but in the case of welded sections, remote from the weld

Figure C.3 — Square and rectangular sections

C.1.3 Location of test samples for impact test

See Figures C.4 and C.5 location of samples a At any point on circumference, but in the case of welded sections, remote from the weld

Figure C.5 — Square and rectangular sections

Test pieces are taken from the samples indicated in Figures C.1 to C.5

[1] ISO 630-1, Structural steels — Part 1: General technical delivery conditions for hot-rolled products 1)

[2] ISO 630-2, Structural steels — Part 2: Technical delivery conditions for structural steels for general purposes 1)

[3] ISO/TS 4949, Steel names based on letter symbols

[4] ISO 6929, Steel products — Definitions and classification

[5] ISO 9001, Quality management systems — Requirements

[6] ISO 10799-1, Cold-formed welded structural hollow sections of non-alloy and fine grain steels — Part 1: Technical delivery conditions

[7] ISO 10799-2, Cold-formed welded structural hollow sections of non-alloy and fine grain steels — Part 2: Dimensions and sectional properties

Tiêu đề	Hot-finished Structural Hollow Sections Of Non-alloy And Fine Grain Steels — Part 1: Technical Delivery Conditions
Trường học	International Organization for Standardization
Chuyên ngành	Standards
Thể loại	tiêu chuẩn
Năm xuất bản	2011
Thành phố	Geneva

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