Standard No.:	GB/T 1979-1980
English Name:	Diagram of a low magnification texture blemish grading of structural steel
Chinese Name:	结构钢低倍组织缺陷评级图
Chinese Classification:	H23    Metal processing property test method
Professional Classification:	GB    National Standard
Implemented on:	1981-5-1
Status:	superseded
Superseded by:	GB/T 1979-2001 STANDARD diagrams for macrostructure and defect of structural steels
Superseded on:	2002-5-1
Abolished on:	2002-05-01
Language:	English
File Format:	PDF
Word Count:	2000 words
Price(USD):	40.0
Delivery:	via email in 1 business day

1. The grading diagrams are divided into Diagram I, Diagram II and Diagram III (see pages 5~42) according to the dimensions and defect properties of steels (billets); the application scopes of such diagrams are as follows: Diagram I: used to assess the defects of round and square steel macrostructures with diameter or side length of 40~150mm. Diagram II: used to assess the defects of round and square steel macrostructures with diameter or side length greater than 150~250mm. Diagram III: used to assess the defects of round and square steel macrostructures with diameter or side length of 40~250mm. Note: for the defect assessment for round, square and flat steel macrostructures with diameter or side length less than 40mm or greater than 250mm, corresponding grading diagram shall be referred according to mutual agreement. 2. The allowableness and acceptance grade of various defects in this standard shall be specified in corresponding technical specifications.