Application of Oil-less Bronze–Graphite Bushings in Hydraulic Press Machines
Application of Oil-less Bronze–Graphite Bushings in Hydraulic Press Machines
High-Performance Self-Lubricating Bronze Bushing Solutions & Technologies. Minimize downtime, extend service life, and reduce costs for dynamic applications.
Oil-less Bronze Graphite Bushes in Steel Production Facilities: Typical Applications & Material Selection Guide
Oil-less bronze graphite bushes—commonly supplied under grades such as JDB, SO#50SP2, BC6C, C86300 + Graphite, C95400 + Graphite—have become indispensable in modern steel plants. Their outstanding self-lubrication, high-temperature resistance (300–450 °C, even 550 °C with special graphite), heavy-load capability, and maintenance-free performance under dust, water vapor, scale, and corrosive atmospheres make them ideal for harsh metallurgical environments.
This guide explains exact application positions in each steelmaking unit, operating conditions, and recommended alloy selections, along with engineering logic and practical case studies.
1. Why Oil-Less Graphite Bushes Dominate in Steel Plants
Key Advantages
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Self-lubrication: Embedded graphite plugs continuously release a film under load.
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High-temperature stability: Al and Mn bronzes maintain strength up to 400–500 °C.
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Scale / water vapor tolerance: No oil film is lost during water cooling.
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Impact resistance: High-strength bases (~750 MPa tensile) withstand shock loads.
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Zero lubrication maintenance: Saves thousands of hours in shutdown labor.
Engineering Priority Hierarchy
When selecting bush materials for metallurgical equipment:
2. Application Map: Where Oil-Less Bronze Bushes Are Used in Steel Plants
Below is a consolidated engineering selection table covering sintering, blast furnace, BOF/secondary metallurgy, continuous casting, hot rolling, cold rolling, and auxiliary equipment.
Table 1 – Typical Application Areas & Recommended Material Selection
Sintering / Pelletizing
| Area / Equipment | Working Conditions | Recommended Material | Hardness (HB) | Max Temp | Why This Material |
|---|---|---|---|---|---|
| Annular cooler car sliders, discharge chute side plates, vibrating screen eccentric bushings | 200–350 °C, extreme dust, heavy impact | C95400 (CuAl10Fe5Ni5) + Graphite or C86300 + Graphite | ≥180 | 400 °C | Al bronze = high strength + oxidation resistance |
| Cooler rail slides, fan bearings | High temperature + dust | CuSn10Zn2 + Graphite (QSn10-2) or JDB-10 | 100–140 | 300 °C | Cost-effective, tough, suitable for medium load |
Blast Furnace (Ironmaking)
| Area / Equipment | Conditions | Material | Hardness | Max Temp | Material Logic |
|---|---|---|---|---|---|
| Mud gun / drill mechanism, hydraulic cylinder trunnions | 150–300 °C, slag, extreme impact | C86300 (Mn bronze) or 650HT (high-strength brass) | ≥220 | 400 °C | Tensile ≥750 MPa for extreme impact |
| Furnace top distribution chute, bell mechanism | High temperature + dust + intermittent heavy load | C95400 or JDB-20 (Al bronze) | ≥170 | 400 °C | High-temp corrosion & long life |
BOF Steelmaking / LF / VD
| Area / Equipment | Conditions | Material | Hardness | Max Temp | Notes |
|---|---|---|---|---|---|
| Converter trunnion bearings, oxygen lance tilting device, ladle turret slide plates | 300–500 °C, thermal radiation, heavy load | 500SP2 or C86300 + High-temp Graphite | ≥220 | 450–550 °C | Requires >500 °C graphite stability |
| Slide gate & sliding supports | High temp, molten steel splash | C95400 or JDB-40 | ≥180 | 400 °C | Anti-metal adhesion (steel splash resistance) |
Continuous Casting
| Area / Equipment | Conditions | Material | Hardness | Max Temp | Notes |
|---|---|---|---|---|---|
| Oscillation table 4-bar linkages, segment roller end bushes, mold oscillator guide rods | 200–350 °C, water vapor, scale, heavy load | C86300 or JDB-650 | ≥220 | 400 °C | Used in >90% of Chinese casters |
| Straightener guide rollers, dummy bar head bushings | High speed + water cooling | C95400 or JDB-20 | ≥170 | 350 °C | Anti-galling at high speed |
Hot Rolling
| Equipment | Conditions | Material | Hardness | Max Temp | Reason |
|---|---|---|---|---|---|
| Walking-beam furnace sliding supports, pusher skids, mill screwdown nuts, shear plates | 300–450 °C, heavy load, thick scale | C86300, C95400, or 500SP2 | ≥210 | 400–500 °C | High strength + self-lubrication → 2–5-year life |
| Coiler pinch roll supports, flying-shear crank bushes | High speed + impact | C93200 (SAE660) + graphite or JDB-10 | 80–120 | 300 °C | Tin bronze fine for high-speed low-load zones |
Cold Rolling & Finishing Lines
| Equipment | Conditions | Material | Notes |
|---|---|---|---|
| Pickling line tension rolls, galvanizing line sink roll bearings, skin-pass support rolls | Acid/alkali corrosion + medium load | CuAl10Fe5Ni5 + Graphite or PTFE composite + bronze | Al bronze = best corrosion resistance |
3. Material Selection Principles for Steel Plant Bushes
Below is a decision matrix summarizing metallurgical-grade bush selection.
Table 2 – Engineering Selection Guidelines
| Condition | Recommended Material | Reason |
|---|---|---|
| Temp > 350 °C | C86300 or C95400 + high-temp graphite (≥500 °C) | Standard graphite decomposes at 400–450 °C |
| Extreme impact (mud gun, tapping equipment) | C86300 | Tensile ≥750 MPa, yield ≥460 MPa |
| Molten steel / molten iron splash area | C95400 or C95500 | Tin bronze fails by melt erosion |
| Acid pickling / galvanizing corrosion | Al bronze or bronze + PTFE layer | Superior corrosion resistance |
| Cost-sensitive but high-longevity needed | JDB-650 (C86300 class) | Best price/performance ratio |
| Ultra-high temperature >450 °C | 500SP2, high-temp series | Special graphite + high-strength matrix |
4. Real Industrial Case Studies in China
Baosteel, Ansteel, Shougang – Continuous Casting Segment
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Material: JDB-650 (C86300 equivalent)
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Result: >99% adoption rate, bush life >2 years
Maanshan Steel & Shagang – BOF Converter Trunnions
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Material: C86300 + high-temperature graphite
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Result: Service life extended to 3–4 years, no seizure even at peak load
Hot Rolling Walking-Beam Furnaces
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Material: 500SP2 or 650HT
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Result: Stable operation above 400 °C, dramatically reduced wear of sliding shoes
5. Summary: One-Sentence Rule for Engineers
Below 300 °C → Tin bronze
300–450 °C → C86300 (high-strength brass)
Above 450 °C or molten steel zone → High-strength brass + high-temp graphite
Use Al bronze or composites only for corrosion or special cases.
Follow this rule and you will almost never select the wrong oil-less graphite bush material for steel plant equipment.
Metal Bushing (Lubricated Metal) -Self-Lubricating Bushing Materials
Bushings are specialized, self-lubricating metal components widely utilized across various industries due to their durability and low maintenance requirements. Self-lubricating metal bushings are engineered to function without additional lubrication in numerous applications, thereby minimizing maintenance needs. These bushings are available in various series and configurations, such as flanged bushings and split bearings, to meet specific application requirements.
Metal-Polymer Anti-Friction Plain Bearings
Metal-Polymer Composite Self-lubricating Bushing Material
Steel Back + Porous Bronze Sinter + PTFE
