Precise cutting and machining are essential first steps in fabricating components from ASTM A515 Gr.65 pressure vessel steel. Using the correct techniques ensures dimensional accuracy, prevents material defects, and maintains the steel's properties for high-temperature service.
Primary Cutting Methods and Best Practices
Thermal Cutting (Plasma, Oxy-Fuel): This is the most common method for profiling plates.
Preheat Requirement: Due to its carbon and manganese content, localized preheating of 150-200°F (65-95°C) is strongly recommended before thermal cutting, especially for thick plates (>40mm/1.5") or in cold environments. This prevents hardening and micro-cracking in the Heat-Affected Zone (HAZ).
Process Control: Use clean, dry fuel gases and optimized cutting speeds. Post-cut, the hardened cut edge (typically 1-3mm deep) must be removed by mechanical machining (milling) before welding or putting into high-stress service.
Mechanical Cutting (Shearing, Sawing, Waterjet): These cold processes avoid thermal effects.
Shearing: Suitable for thinner plates. Ensure blades are sharp and properly aligned to prevent edge deformation or cracking.
Abrasive Waterjet Cutting: An excellent, but more costly, option that produces no HAZ and is ideal for complex shapes. It requires no preheat.
