DL/T 882-2022 in English

Background of Standard Revision and Technological Evolution

As the basic terminology standard for metal supervision in the thermal power generation industry, the revision of DL/T 882-2022 reflects the development needs of new technologies such as ultra-supercritical units and high-temperature alloys in the past 15 years. Compared with the 2004 edition, breakthroughs are mainly achieved in three aspects:

Technical analysis of core terms

4.4 Brittleness of metals

The standard clearly defines hydrogen embrittlement (Article 10.2.3) as "the embrittlement phenomenon of metal materials caused by the combined action of hydrogen and stress", a typical example is the stress corrosion cracking of boiler headers in a wet H2S environment. The new version adds the term "hydrogen corrosion" to distinguish the microscopic mechanisms of reversible hydrogen embrittlement and irreversible hydrogen damage.

7.5 Creep performance

Innovatively divides creep cracks into four types: Type I (main crack) to Type IV (grain boundary diffusion type), corresponding to different temperature stress conditions. Failure analysis of the main steam pipe of a 660MW unit showed that immediate replacement was required when the proportion of type IV cracks reached 73%.

Implementation Suggestions

1. Term Mapping: Establish a comparison table of old and new terms, focusing on mastering 23 definition modifications such as "Metal Technical Supervision"
2. Training Focus: Carry out special training on newly added surface technical terms such as laser cladding
3. Database Construction: Embed standard terms into the metal supervision information system to ensure the standardization of inspection report terms