How to judge the quality grade of alloy structural steel raw materials?

Qualified alloy structural steel must first pass spectral chemical inspection to ensure all alloy element content meets national or international standard ranges. Metallographic testing checks internal grain uniformity and avoids harmful segregation, inclusions or banded structures. Mechanical tests cover tensile strength, yield strength, elongation and room/low-temperature impact toughness. Non-destructive ultrasonic inspection detects internal pores, shrinkage cavities and forging cracks. Unqualified batches will lead to sudden fracture of load-bearing parts under operation and serious equipment safety hazards.