NB/T 47016-2023Mechanical property tests of product welded test coupons for pressure equipments (English PDF)

Foreword

This document was drafted in accordance with the provisions of GB/T 1.1-2020 "Directives for standardization - Part 1: Rules for the structure and drafting of standardizing documents".

This document replaces NB/T 47016-2011 "Mechanical property tests of product welded test coupons for pressure equipments". Compared with NB/T 47016-2011, in addition to structural adjustments and editorial changes, the main technical changes are as follows.

a) MODIFY the scope of application, adding the relevant provisions for welded test coupons of zirconium products (see Chapter 1);

b) ADD the welded test coupons of the head split joint and spherical container products [see 4.4 a) and 4.4 c)];

c) ADD the qualified indicators of tensile strength and bending performance of zirconium container welded joints (see 7.1.4.1 and Table 3);

d) MODIFY the qualified indicators of full weld metal tensile test (see 7.1.4.2);

e) MODIFY the qualified indicators of impact absorption energy of boiler steel welded joints (see 7.3.4 b)];

f) ADD the provisions for qualified indicators of impact absorption energy of welded joints with two metal material codes as the parent material (see 7.3.4 c)].

1 Scope

This document specifies the preparation of welded test coupons, specimen preparation, inspection methods, qualified indicators for pressure equipment (boilers, pressure vessels and pressure pipes).

This document is applicable to the mechanical and bending performance tests of welded test coupons (including welded test plates, simulation rings, certification rings) of steel, aluminum, titanium, copper, nickel, and zirconium pressure equipment products.

This document is not applicable to the mechanical and bending performance tests of welded test coupons of gas cylinder products.

2 Normative references

The contents of the following documents constitute essential clauses of this document through normative references in the text. Among them, for dated references, only the version corresponding to that date is applicable to this document; for undated references, the latest version (including all amendments) is applicable to this document.

GB/T 228 (all parts) Metallic materials - Tensile testing at ambient temperature

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

GB/T 2652 Destructive tests on welds in metallic materials - Longitudinal tensile test on weld metal in fusion welded joints

GB/T 2653 Bend test methods on welded joints

GB/T 3375 Welding terminology

NB/T 47014 Welding procedure qualification for pressure equipments

3 Terms and definitions

The terms and definitions defined in GB/T 3375 and NB/T 47014 apply to this document. If there is any inconsistency, the terms and definitions of NB/T 47014 shall prevail.

If the specimen thickness T ± 38 mm and two or more specimens are used, each specimen shall meet the above requirements.

4 General

4.1 In addition to complying with the provisions of this document, the mechanical property inspection of product welded test coupons shall also comply with the provisions of relevant safety technical specifications, standards, design documents.

4.2 The materials used for the test coupons shall be taken from qualified raw materials; they shall be of the same standard, code (designation, steel grade), specification (limited thickness), heat treatment state as the materials of the pressure equipment components they represent.

4.3 Welded test coupons for pressure equipment products are divided into plate test coupons and tubular test coupons; tubular test coupons refer to pipes and rings.

4.4 Welding of product welded test coupons.

4.6 After the test coupon has been inspected visually and tested non-destructively, it is allowed to avoid welding defects and prepare specimens.

4.7 The specimen is allowed to be cold leveled before removing the weld excess height.

4.8 When the test coupon adopts two or more welding methods, or welding procedures with different important factors and supplementary factors, the welded joints of all welding methods or welding procedures shall be tested for mechanical properties and bending properties.

4.9 The test coupon shall be marked with the following identification marks.

5 Test coupon preparation

5.1 The size and quantity of the test coupon shall meet the requirements for cutting the test coupons (including those for re-testing). The test coupons can also be cut directly on the weldment.

5.2 Test coupon size. The length of the plate test coupon is greater than or equal to 300 mm; the width is greater than or equal to 250 mm. The length of the tubular test coupon is greater than or equal to 250 mm. See Figure 1 and Figure 2 for test coupon dimensions.

6 Mechanical properties test category and specimen of test coupon

6.1 When the relevant specifications, standards and design documents of pressure equipment have impact test requirements for welded joints, product welded test coupons shall be subjected to impact test.

6.2 The full weld metal tensile test is only applicable to the longitudinal welded test coupons of Class A boiler drum and header components.

6.3 The allowable tolerance of the specimen size shall be determined in accordance with the relevant standards or technical documents.

6.4 The mechanical properties and bending properties test category and the number of specimens shall be in accordance with the provisions of Table 1.

6.6 The length of the discarded part at both ends of the test coupon varies with the welding method and plate thickness.

6.7 The specimen blank is cut by cold working method, or hot working method; however, the oxide layer and other materials need to be removed by cold working method to expose the metallic luster.

6.8 After the specimen passes the inspection and marked, it is stamped with a steel stamp or permanent mark.

7 Inspection method and qualified index

8 Retest

8.1 If a certain item of mechanical properties and bending properties test fails, it is allowed to resample from the original test coupon for retest of unqualified items.

9 Other tests

For welded product test coupons with other requirements such as high temperature tensile properties, corrosion resistance, hardness, the test methods and qualified indicators shall comply with the relevant standards and design documents. […]