NB/T 47009-2017Low-alloy steel forgings for low temperature 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 Standard replaces NB/T 47009-2010 "Low-alloy steel forgings for low temperature pressure equipment". Compared with NB/T 47009-2010, the main technical changes are as follows.

- CANCEL the content regarding design pressure and design temperature in the scope;

- ADD 06Ni9D alloy steel forgings for use at -196 °C;

- REFINE the relevant requirements for ordering information;

- ADD the requirements for macroscopic examination;

- MODIFY the KV2 impact test value for 08Ni3D forgings at -100 °C to 60 J;

- RAISE the quality grade for ultrasonic testing of steel forgings;

- MODIFY the acceptance criteria for weld repairs. Annex A of this Standard is normative.

1 Scope

This Standard specifies the terms and definitions, ordering information, technical requirements, test methods, inspection rules, marking and quality certificate for alloy steel forgings for low temperature pressure equipment.

2 Normative references

The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.

GB/T 222 Permissible tolerances for chemical composition of steel products

GB/T 223 Methods for chemical analysis of iron, steel and alloy (applicable parts)

GB/T 226 Test method for macrostructure and defect of steel by etching

GB/T 228.1 Metallic materials - Tensile testing - Part 1: Method of test at room temperature

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

GB/T 4336 Carbon and low-alloy steel - Determination of multi-element contents - Spark discharge atomic emission spectrometric method (routine method)

GB/T 6394 Determination of estimating the average grain size of metal

GB/T 10561 Determination of content of nonmetallic inclusions in steel - Micrographic method using standard diagrams

GB/T 20066 Steel and iron - Sampling and preparation of samples for the determination of chemical composition

GB/T 20123 Steel and iron - Determination of total carbon and sulfur content - Infrared absorption method after combustion in an induction furnace (routine method)

GB/T 20124 Steel and iron - Determination of nitrogen content - Thermal conductimetric method after fusion in a current of inert gas (routine method)

NB/T 47013.3 Nondestructive testing of pressure equipment - Part 3: Ultrasonic testing

NB/T 47013.4 Nondestructive testing of pressure equipment - Part 4: Magnetic particle testing

NB/T 47013.5 Nondestructive testing of pressure equipment - Part 5: Penetrant testing

3 Terms and definitions

For the purpose of this document, the following terms and definitions apply.

4 Ordering information

Purchase contracts referencing this Standard shall include the following contents.

a) Product name;

b) Ordering drawing;

c) Standard number;

d) Material designation;

e) Forging grade;

f) Quantity (or mass);

g) Delivery condition (including heat treatment and surface requirements);

h) Non-destructive testing requirements;

i) Supplementary technical requirements.

5 Technical requirements

7 Inspection rules

7.2.2 Tensile test specimens shall be the R4 type specimen specified in GB/T 228.1. If sampling dimensions are restricted, agreed upon between the supplier and the purchaser, the R7 type specimen specified in GB/T 228.1 may be used.

7.2.3 Impact test specimens shall be standard-size Charpy V-notch specimens specified in GB/T 229.