1. Plasma Cutting: Most Versatile for Medium-Thick Plates
Applicability: Ideal for Q355NH plates with thicknesses of 3–50mm, especially for workpieces requiring relatively high cutting precision (e.g., structural parts with irregular shapes, landscape sculpture components).
Core Advantages:
Fast cutting speed (2–3 times faster than flame cutting for 10–20mm plates), suitable for batch processing.
Narrow heat-affected zone (HAZ, usually 1–3mm), reducing the risk of hardening and cracking in the cut edge-critical for Q355NH's susceptibility to thermal brittleness.
Can cut complex shapes (e.g., curves, holes) by matching numerical control (CNC) systems, meeting diverse design needs.
2. Flame Cutting: Cost-Effective for Thick Plates
Applicability: Mainly used for Q355NH plates ≥12mm, such as large structural parts (e.g., bridge girders, container frames) where high precision is not the top priority.
Core Advantages:
Low equipment cost (only requires a cutting torch, oxygen cylinder, and acetylene cylinder), suitable for on-site construction or small-scale workshops.
Capable of cutting extra-thick plates (up to 200mm), which is difficult for plasma cutting with low-power equipment.
3. Cold Saw Cutting: Best for Thin Plates and Precision Cuts
Applicability: Suitable for Q355NH plates ≤10mm, especially for small workpieces requiring smooth edges (e.g., decorative strips, small brackets) or subsequent secondary processing (e.g., drilling, bending).
Core Advantages:
No thermal impact-avoids HAZ formation, hardening, or stress-induced cracking, which is perfect for Q355NH's thin plates (prone to thermal deformation).
High cutting precision (edge flatness ≤0.1mm) and smooth surface, reducing the need for post-cut grinding.
4. Shearing Cutting: Efficient for Straight-Line Thin Plates
Applicability: Designed for Q355NH plates ≤6mm, used for mass production of workpieces with straight edges (e.g., flat plates, rectangular components for guardrails).
Core Advantages:
Ultra-high efficiency-can cut multiple thin plates stacked together (up to 3–5 layers for 2mm plates), saving time for batch processing.
Low cost and simple operation, suitable for workshops with high-volume, standardized production needs.
