GB/T 34904-2017 in English

《GB/T 34904-2017球墨铸铁件 超声检测》由TC54（全国铸造标准化技术委员会）归口，TC54SC2（全国铸造标准化技术委员会铸铁分会）执行，主管部门为国家标准化管理委员会。

ChinaStandards.net is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.

This standard is developed in accordance with the rules given in GB/T 1.1-2009.

This standard was proposed by and is under the jurisdiction of SAC/TC 54 National Technical Committee on Foundry of Standardization Administration of China.



Spheroidal graphite iron castings - Ultrasonic testing

1 Scope

This standard specifies terms and definitions, general requirements and testing method for the ultrasonic testing of spheroidal graphite iron casting.

This standard is applicable to the ultrasonic testing for defects on general-purpose spheroidal graphite iron castings and spheroidal graphite iron castings with the thickness of 10mm~500mm.

This standard is not applicable to the testing of the nodularity of spheroidal graphite iron castings and the testing method of through-transmission technique.

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 9445 Non-destructive testing - Qualification and certification of NDT personnel
GB/T 12604.1 Non-destructive testing - Terminology - Terms used in ultrasonic testing
GB/T 19799.1 Non-destructive testing - Ultrasonic testing - Specification for calibration block No.1
GB/T 19799.2 Non-destructive testing - Ultrasonic testing - Specification for calibration block No.2
GB/T 27664.1 Non-destructive testing - Characterization and verification of ultrasonic test equipment - Part 1: Instruments
GB/T 27664.2 Non-destructive testing - Characterization and verification of ultrasonic test equipment - Part 2: Probes
GB/T 27664.3 Non-destructive testing - Characterization and verification of ultrasonic test equipment - Part 3: Combined equipment
JB/T 9219 Spheroidal graphite cast iron - Test method for ultrasonic sound velocity

3 Terms and definitions

For the purposes of this document, the terms and definitions given in GB/T 12604.1 and the following apply.

3.1

dross

fine slag particles (oxides, sulphides, etc.) in the rim zone of castings, as well as slag that has a lower density than molten metal and accumulates on the surface of the molten pool or the castings

4 General requirements

4.1 Order information

The following information shall be available at the time of order:

a) the areas of the spheroidal graphite iron casting and the number or percentage of castings subjected to ultrasonic testing;

b) quality level of each part of the spheroidal graphite iron casting;

c) requirements for testing process;

d) other special requirements for testing, if any.

4.2 Personnel qualification

The ultrasonic testing personnel shall obtain corresponding qualification certificates in accordance with GB/T 9445 or other standards which are considered to be equivalent.

4.3 Testing equipment

4.3.1 Ultrasonic instrument

4.3.1.1 The ultrasonic instrument shall meet the requirements given in GB/T 27664.1 in terms of performance and shall have the following characteristics:

a) range: from at least 10 mm to 2,000mm continuously selectable, for longitudinal and transverse waves transmitted in steel;

b) gain: adjustable in 2dB maximum steps over a range of at least 80dB with a measuring accuracy of 1dB;

c) it shall at least meet the requirement that two types of probes, i.e., dual-element probe and single-element probe, are adjustable for nominal frequencies from 0.5MHz to 5MHz.

4.3.1.2 The combined equipment for ultrasonic testing shall be checked regularly by the operator according to GB/T 27664.3.

4.3.2 Probes

4.3.2.1 Dual-element probe shall be used for the testing of areas close to the test surface. For the detection of near-surface defects, the use of dual-element or angle-beam probe is recommended.

4.3.2.2 For areas with special geometry, angle-beam probes can be used for the testing. Generally, the angle-beam probe shall be with a nominal refraction angle of 45° to 70° and a maximum detectable sound path of 100 mm.

4.3.3 Ultrasonic instrument and probe

4.3.3.1 The frequency of the instrument and the probe shall meet the requirements of GB/T 27664.2 and GB/T 27664.3 respectively.

4.3.3.2 Probes with higher frequencies are normally used to test castings with small wall thicknesses and high quality requirements. The zoning for casting based on the wall thickness is as shown in Figure 1.

Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 General requirements
5 Testing method