What is steel forging?

Steel Forging Encyclopedia

■What is its essence?

Steel forging = steel billet + high-temperature forging (repeatedly hammered into shape, like blacksmithing).
Core purposes:
▸Compacting the interior: Eliminating air bubbles and cracks (inherent defects in castings).
▸Directional strengthening: Allowing metal grains to extend along the direction of force (forming "metal flow lines"), improving strength and toughness.

■Forging process: Three-step shaping

Heating and softening: The steel billet is heated to a high temperature (approximately 1100℃), becoming malleable like dough.
Heavy hammer shaping: Repeated hammering with a pneumatic hammer/hydraulic press to create shapes such as gears and shaft ends.
Key functions: Densifying the internal structure (eliminating porosity and shrinkage).
Refining grains (more wear-resistant and impact-resistant).
Heat treatment to determine properties: Quenching + tempering adjusts hardness or toughness (e.g., excavator gears need to be hard, springs need to be tough).

■Advantages Compared to Other Processes

Advantages of Casting/Machining Parts vs. Steel Forgings
Internal structure resembles a honeycomb (with pores) → Solid and non-porous → Pressure-resistant and leak-proof
Disordered grains → Directed grain arrangement → Doubled impact resistance
Cut-resistant parts break metal fibers but retain intact flow lines → Stronger fatigue resistance
Thick parts have weak core performance; consistent strength and toughness inside and out

■Where are steel forgings used? Specifically designed for applications requiring high durability

High-impact scenarios:
Crusher hammers, excavator bucket teeth → Hard-hitting performance.
High-pressure, high-risk areas:
Hydraulic valve blocks, pipe flanges → Dense, explosion-proof, zero leakage.
High fatigue life requirements:
Engine crankshafts, gear shafts → Unbreakable after millions of cycles.
Special performance requirements:
Corrosion resistance → Stainless steel forgings (e.g., chemical pumps)
High temperature resistance → Alloy steel forgings (e.g., power plant valves)

■Why choose it? Long-term cost savings!

Doubled lifespan: Wear-resistant and durable, reducing downtime for replacements (e.g., forged gears have a lifespan three times that of castings).
Low failure rate: No internal defects, avoiding sudden fracture accidents.
Possible lightweighting: Forgings can be thinner and lighter than castings for the same load (saving materials and energy).