Q: What are the material properties of ASTM A519 94B17 steel pipe?
A: This steel pipe is a chromium-molybdenum alloy seamless steel pipe specified in the ASTM A519 standard, designated 94B17 (similar to 4117 steel). Its core composition is low-carbon steel (C≈0.17%), containing 0.8-1.1% chromium and 0.15-0.25% molybdenum. It exhibits excellent cold formability and weldability, while achieving a good balance of strength (tensile strength ≥520 MPa) and toughness through heat treatment.
Q: What are the significant differences compared to 94B30/94B40?
A: The key difference lies in carbon content:
94B17 (0.17% C) prioritizes cold working and weldability, offering the lowest strength but the highest ductility.
94B30 (0.30% C) is a general-purpose balanced steel.
94B40 (0.40% C) emphasizes high strength but requires strict temperature control during welding. Typical Applications: 94B17 is preferred for applications requiring deep drawing or complex welded structures.
Q: What are the main industrial applications?
A: Typical scenarios include:
Lightweight automotive chassis components (such as control arms and steering knuckles);
Fluid delivery systems (high-pressure hydraulic pipes);
Welded structural components for construction machinery;
Fasteners or connectors requiring cold heading/bending.
Its low crack susceptibility makes it particularly suitable for mass welding production.
Q: What are the special requirements for the heat treatment process?
A: Recommended process chain:
Normalizing (900°C ± 10°C air cooling) improves microstructure uniformity;
Carburizing and quenching (case hardening) improves wear resistance;
Tempering (400-550°C) relieves stress.
Note: Low carbon content limits hardenability, so caution is advised when using section thicknesses greater than 50mm.
Q: Practical suggestions for processing and corrosion protection. A:
Cutting: Use high-speed steel tools with emulsion cooling to prevent tool sticking.
Welding: Preheating is not required (for thicknesses < 25mm), but ER80S-D2 welding wire is recommended.
Corrosion Protection: Phosphate coating and baking varnish enhance weather resistance. Galvanizing is recommended for marine environments.
