Maximizing Equipment Reliability in India's Steel Plants Through Proper Lubrication Practices

Overview of India's Steel Industry

India's steel sector ranks among the world's largest, serving as a vital pillar in the nation's economic growth. As of 2024, India is the second-largest producer of crude steel, benefiting from abundant domestic iron ore and coal resources. The sector is largely driven by infrastructure growth, urbanization, and expanding demand from key industries like construction, automotive, and manufacturing. Both public and private players, including giants like Tata Steel, JSW Steel, and Steel Authority of India Limited (SAIL), dominate the market. With the government's focus on initiatives like "Make in India" and infrastructure development, the steel industry is poised for further growth, contributing significantly to GDP and employment generation.

Steel Manufacturing

Steel manufacturing is a complex process & involves various steps. The main raw materials required for initial pig iron are - iron ore, coke and flux. Iron ore chunks of appropriate quality and composition are crushed to the required size to be fed into a blast furnace. The Iron ore fines are converted into sinter by baking at a temperature where the grain structure becomes flexible, i.e. re-crystallization temperature. Coke is obtained by heating coal in the absence of air in Coke Oven Batteries. Thus iron ore, sinter, coke and flux are fed into a blast furnace to produce pig iron. This pig iron is the raw material for steel production. Molten iron is blasted with oxygen, in order to reduce the carbon content from the pig iron, turning into steel. This process is carried out in huge converters.

Now the molten steel takes various paths, either directly shaped to Blooms, Slabs or Ingots. Then it is further rolled in various shops to obtain the final products such as - Rails, Wire Rods, Bars, etc.

Structure and Lubrication Requirements of Steel Plants

An integrated steel plant is generally organized into four key sections: Iron Production, Steel Production, Rolling and Finishing, and Auxiliary Operations.

• Iron Making: This includes raw material blending yards, beneficiation plants, sinter plants, coke ovens, and blast furnaces. The equipment here generally operates under high temperatures and in abrasive, dusty, and corrosive environments, often at lower speeds.
• Steel Making: Comprising LD furnaces, continuous casters, and lime plants, equipment in this group faces high temperatures and similar abrasive and corrosive conditions as in the Iron Making group.
• Rolling and Finishing: This includes Hot Strip Mills, Cold Rolling Mills, and Bar and Wire Rod Mills. The equipment here is subjected to high impact loads, water and scale ingress, elevated temperatures near reheating furnaces, and higher speeds and unit loads.
• Auxiliary Operations: This section supports the core operations of the steel plant. It typically includes utilities such as power generation, water treatment, air separation plants, and maintenance workshops. These operations ensure the smooth functioning of the primary production groups by supplying essential resources and services. Equipment in these areas may not face the same extreme conditions as in the core sections but must still handle continuous operation, reliability challenges, and efficiency optimization.

The Role of Lubrication in Equipment Reliability

In steel plants, ensuring the reliability of equipment and adopting better maintenance practices directly impacts productivity and equipment health. Generally, maintenance costs account for 10-15% of production costs. Proper lubrication can prevent numerous maintenance issues, facilitating smooth plant operations. While lubricant costs are only a small fraction of total maintenance costs, improper lubrication can cause over 30% of breakdowns. Investing in high-quality lubricants can be slightly more expensive but pays off through reduced downtime, enhanced reliability, and decreased spare part usage.

Factors to Consider When Selecting Lubricants

When selecting lubricants for steel plant equipment, several factors need to be considered:

1. Engineering Requirements: These include load, speed, surface finish, and temperature rise. Appropriate oil viscosity (lubricant grade) typically satisfies these requirements.
2. Service Conditions: These are addressed by selecting suitable additive packages (lubricant type) that offer protection against rust, oxidation, scuffing, corrosion, and foaming.

Types of Lubricants Used in Steel Plants

Steel plants use various lubricant grades, such as hydraulic oil, gear oil, circulating oil, turbine oil, metal working fluids and greases, which are tailored to the specific needs of different equipment:

• Hydraulic Oil:Antiwear hydraulic fluids, fire-resistant fluids, and high-water-based fluids are common in steel plants.
• Gear Oil:Essential for lubricating heavily loaded gears and bearings, providing wear protection, and reducing friction in gearboxes and other applications.
• Turbine & Circulating Oil: Turbine and circulating oils are essential for lubricating various types of machinery in steel mills. These oils, for instance, are specifically circulating oils used to lubricate roller bearings in rolling mill equipment, ensuring smooth operation and reducing wear.
• Metal Working Fluids: Include soluble oils for machine operations and neat cutting oils for cutting, grinding, rolling, and drawing.
• Greases:Used for the lubrication of machine gears and bearings. It is used in continuous casting equipment, slabbing mill equipment, hot-rolling equipment, pickling lines, and cold reduction equipment.

Designation of Service Parameters

To select the correct lubricant, various operational parameters must be identified, such as speed, load, temperature, and moisture content. The equipment load in steel plants can be classified based on American Foundrymen's and Manufacturers' Association (AFMBA) guidelines, and speed can range from very low to very high.

Challenges in Steel Plant Lubrication

Steel plants pose several lubrication challenges, including high speeds, impact loads, temperatures, and the ingress of cooling water and scale. Selecting lubricants that offer thermal stability, high viscosity index, and excellent demulsibility properties is crucial. Greases with specific base types can help mitigate issues related to water washout and pumpability, especially in cold temperatures.

Maintaining Lubricant and Equipment Health

In the Steel industry, machinery maintenance is handled either internally or through third-party and local service providers. Maintenance strategies are continually evolving to reduce costs and boost production efficiency. Key improvements include the use of high-quality lubricants with extended drain intervals, regular oil analysis and filtration, and timely oil changes.

Large-scale companies often have dedicated maintenance departments responsible for preventive maintenance and repairs. Smaller companies tend to outsource these services to third-party providers.

For metalworking fluids (MWFs), there is no standard drain interval for a complete oil change, as MWFs require specialized technical knowledge for proper usage and upkeep. Similar to other industries, the demand for comprehensive chemical management is growing in the metal sector due to increased awareness of maintenance practices.

For other lubricants, top-ups are typically needed every two to six months, depending on machine usage. Complete lubricant replacement is less frequent, often occurring every one to two years. Greases, on the other hand, are fully replaced every 20 to 30 days, depending on the machine's operation. Oil levels are checked weekly, with top-ups performed if levels fall below the minimum. Oil analysis is conducted, usually monthly/quarterly, to prevent contamination, with a sample sent to labs for testing.

Conclusion

Effective lubrication is critical for the efficient and reliable operation of integrated steel plants. Selecting the right lubricant, tailored to the specific needs of various equipment and operational conditions coupled with proper oil care and condition monitoring schedules can significantly reduce maintenance costs and improve productivity. Although high-quality lubricants might incur a slightly higher initial cost, the benefits in terms of equipment longevity, reduced downtime, and overall operational efficiency will certainly offset the higher initial cost.

About the Author

Jayakar Shinde is an Engineering Graduate having 38 years of experience in the petroleum industry covering a wide spectrum of quality assurance, sales, technical services, and OEM business. He is currently Head of Technical Services at Lube BU mentoring a specialist team of 11 Technical Services Managers. He has vast experience in Quality Assurance, Field Technical Services, Direct Lube Sales, Territory Manager, Regional Technical Service Manager, Manager R&D, Regional OEM Manager, and Head OEM Approvals. You can contact Mr. Jayakar Shinde at shindejj@bharatpetroleum.in.

Jayakar Shinde
Head Technical Services (Lubes) | BPCL

Abhirup Roy is a seasoned Technical Services Manager at Bharat Petroleum Corporation Limited (BPCL) with over 9 years of experience. He holds a B.Tech in Mechanical Engineering from NIT Surat. He specializes in product management, business development, and technical support for industrial lubricants. His expertise includes managing field trials, offering technical training, and leading teams. He has played a key role in product development and market strategy. You can contact Mr. Abhirup Roy at abhiruproy@bharatpetroleum.in

Abhirup Roy
Manager Technical Services (Lubes) | BPCL