GB/T 37400.15-2019 "General Technical Conditions for Heavy Machinery, Part 15: Nondestructive Flaw Detection of Forged Steel Parts" specifies the nondestructive detection methods and mass grades applicable to forged steel parts used in heavy machinery. This standard covers the specific implementation methods of ultrasonic, magnetic particle and penetration testing, and specifies the scope of application and detection requirements of various detection methods. The standard aims to ensure the safety and Reliability of forged steel parts during manufacture and use, and to evaluate possible defects and damage through nondestructive testing to improve the mass and performance of forged steel parts. The standard refers to a number of relevant national and international standards, including testing conditions, personnel qualification identification, test block production and equipment requirements, etc., providing a unified technical guide and quality control standards for the industry.