1. Raw Material Modification
- (1) Annealing Process Upgrade
Phasing out backward coal-fired furnaces, adopting bell-type annealing furnaces with nitrogen (or nitrogen-hydrogen mixture) protection to ensure uniform hardness and prevent surface decarburization
- (2) Continuous Rolling & Drawing
Technology maturity: Line speed increased from 0.25 m/s to 1-4 m/s
- (3) Pollution Control in Pickling
Acid-waste treatment technologies now mature
2. Chain Plate High-Speed Punching
- Progressive high-speed punching dominates the industry.
- Large plates: Secondary punching or steel ball extrusion (world-leading techniques)
3. Hard Alloy for Punching Dies
- Cemented carbide applied to chain plate punching dies for wear resistance
4. Deburring via Polishing Machines
- Vibratory finishing machines replace manual deburring
5. High-Speed Pin Cutting
- Precision cutting technology for pins promoted to reduce deformation
6. Pin Chamfering Innovations
- (1) Large滚筒加工法；⑵ 石英砂取代黄砂；⑶ 冷镦法。
- (1) Large滚筒加工法；⑵ 石英砂取代黄砂；⑶ 冷镦法。
- (1) Large滚筒加工法；⑵ 石英砂取代黄砂；⑶ 冷镦法。
7. Pin Super-Polishing
- Planetary barrel polishing with specialty abrasives for micron-level smoothness
8. Sleeve Processing
- Large sleeves: Seamless tubing
- Small/medium sleeves: Coiling (optimal: Bihler machine and MRP pre-bending)
- Critical chains: Cold extrusion for precision
9. Roller Manufacturing
- High-speed chains: Coiling method
- Small/medium rollers: Cold extrusion
- 48A+ specifications: Seamless tube cutting
10. Material Standards Comparison
| Component | US/JP Materials (SAE) | China Common Materials | Impact |
|---|---|---|---|
| Chain Plate | 1045/1050 (C 0.45-0.50%) | Low-carbon steel (C≤0.40%) | ▼ Tensile strength |
| Roller | 1035/1045 (C 0.35-0.45%) | Q235 (C 0.12-0.20%) | ▼ Wear resistance |
| Sleeve | 1019/1022 (Mn 1.0-1.3%) | 20Mn (Mn 0.7-1.0%) | ▼ Fatigue life |
| Pin | 8620/4340 (Ni-Cr-Mo alloy) | 40Cr (Cr 0.8-1.1%) | ▼ Impact toughness |
Result: Chinese chains fail to meet avg. breaking load in ANSI/ISO standards
11. Heat Treatment Advances
- (1) Thin carburizing layers preferred
- (2) Hardness gradient replaces carbon concentration testing → gentle gradients reduce brittleness
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- (3) Controlled-atmosphere quenching & carbonitriding
- (4) Propane gas carburization
- (5) Replacing rotary furnaces with box-type multi-purpose furnaces for thick layers
- (6) Aqueous quenching replaces oil → reduces pollution
12. Special Techniques
- Coating, stainless steel heat treatment, chromizing
- Thick-plate punching/notching, S-type roller chain bending — now solvable
13. Running-in & Lubrication
- Two running-in methods
- Automatic oiling systems eliminate month-end quality fluctuations (月底效应)
- Lubricant function: Friction reduction & anti-wear
14. Production Layout Optimization
- (1) Zone division by product categories
- (2) Equipment arrangement by process type
- (3) Outsourcing parts when quality/cost/delivery meet standards