The A588 steel plate (a weather-resistant steel, similar to Corten) typically undergoes the following heat treatment processes to achieve optimal mechanical properties and corrosion resistance:
1. Normalizing
Temperature: 900–925°C (1652–1697°F)
Process: Heated above the upper critical temperature, held for sufficient time, then air-cooled.
Purpose: Refines grain structure, improves toughness, and enhances weathering resistance.
2. Quenching & Tempering (for higher strength grades)
Quenching: Heated to 870–925°C (1600–1697°F), then rapidly cooled (water or oil).
Tempering: Reheated to 540–650°C (1004–1202°F), then air-cooled.
Purpose: Increases strength while maintaining ductility (used for A588 Grade B/K).
3. Stress Relieving (Optional)
Temperature: 595–675°C (1103–1247°F)
Process: Slow heating, holding, and controlled cooling.
Purpose: Reduces residual stresses from welding or forming.
Key Notes:
A588 is commonly supplied in the normalized condition for structural applications.
Unlike A606, A588 is often used in bridges and heavy structures, requiring stricter mechanical properties.
Exact temperatures depend on thickness and manufacturer specifications (refer to ASTM A588/A588M).
