1. Material Preparation and Forging
– The hammer body, piston, and tamping rod blanks are forged using the die forging process to ensure continuous metal flow and avoid casting defects; cutting is performed using CNC flame cutting machines or plasma cutters, with dimensional errors ≤ ±0.5mm.
– Forging temperature is controlled at 1100-1200℃, followed by annealing to relieve internal stress.
2. Heat Treatment
– Hammer body: Quenching and tempering, hardness HRC28-32, to enhance overall mechanical properties.
– Piston: Carburizing and quenching, carburized layer depth 0.8-1.2mm, surface hardness HRC58-62, core hardness HRC30-35.
– Tamping rod: Overall quenching and medium-temperature tempering, hardness HRC52-58, followed by straightening treatment, with straightness error ≤0.5mm/m.
3. Machining
– Precision machining is performed using CNC lathes and machining centers; hammer body inner surface roughness Ra ≤ 0.8μm, piston-to-cylinder fit clearance controlled at 0.03-0.05mm to ensure smooth sealing and movement.
– Threaded holes and pinholes are machined using tapping machines and drilling machines, with dimensional accuracy in accordance with GB/T 197 standards.
4. Surface Treatment
– Hammer bodies and side plates are coated with paint or powder coating, with an anti-rust primer as the base layer and wear-resistant topcoat, thickness ≥ 80μm, to prevent corrosion and rust.
– Piston surfaces can be hard chrome plated with thickness 0.02-0.03mm to enhance wear resistance.。