Corrosion and abrasion damage to plant and manufacturing equipment are ongoing issues in the Pulp & Paper industry. In Part 1 of this series, we explored the common corrosion types, where they are most commonly found, and how they exhibit. In this part, we will consider the varieties corrosion may exhibit and the forms it may take. This knowledge will help business owners and operators avoid disrupted operations and corrosion-related downtime.
Corrosion and Abrasion Types to Expect in Pulp & Paper Mills and Factories
When producing pulp and paper, many production aspects can expose materials and machinery to corrosion and abrasion. The most common forms of these are listed below.
Pitting Corrosion
Pitting corrosion occurs on carbon steel and cast-iron alloys when the passivated natural oxide (Fe2O3) layer on a metallic surface is disturbed. The area has an anodic (low pH) reaction while the covered areas remain cathodic. Corrosion ‘pitting’ commences in the anodic region, and as deterioration progresses, the pit deepens, and the cavity may exceed the wall thickness resulting in leaks and structural failure.
Graphitic Corrosion
Commonly seen in cast iron and ductile iron when buried in acidic soils or exposed to mildly acidic waters, Graphitic Corrosion occurs when iron (Fe) leaches out of the casting into the soil or water flows, leaving behind a weakened matrix of graphite and iron oxides. The remaining matrix of graphite and iron oxides is weak and soft and, if left unaddressed, can lead to collapse or structural failure. Influences include soil moisture content and any contamination.
Galvanic Corrosion
Two dissimilar metals cause this form of corrosion when differing electromotive potentials meet one another in the presence of a common electrolyte. In this case, the less noble metal becomes anodic and goes into an ionic solution, sacrificing itself to protect its more noble cathode.
Microbiologically Influenced Corrosion (MIC)
MIC is commonly found in equipment and areas in contact with water in aerobic and anaerobic conditions. Mild steel and ductile iron in spaces such as piping, valves, pumps, and associated structural members are compromised in the acidic environment created by this type of corrosion.
Acid Attack
Chemical attack frequently occurs when acids are present. The area’s most prone to attack are often containment and dose mixing stations. In concrete areas, etching will appear, progressing to cement paste breakdown and aggregate exposure with rebar corrosion and spalling.
Mechanical Abrasion
Many Pulp & Paper plant machines are vulnerable to abrasion and erosion, including de-barkers, paper rollers, and other equipment with components under extreme pressure. While each of these is a robust piece of machinery with a high-volume output and processing ability, without additional protection, damage is inevitable.
Prevent Corrosion with Chesterton Solutions
Proper Equipment Lubrication with the Chesterton LubriCup and High-performance Grease Solutions can significantly influence industrial equipment and processes. Adequate lubrication is challenging in all industries; however, correct lubrication is vital for longevity and smooth production.
Manual lubrication is susceptible to error. Issues arising may include:
- Ensuring optimal greasing of components
- Providing neither under nor over-greasing
- The need to halt production to lubricate parts
- Machine contamination and containment issues
Efficiency and dependability can be dramatically improved by implementing industrial-grade technologies with additional automation, creating a cost-effective and reliable solution.
Chesterton LubriCup has revolutionised the art of proper greasing. The automatic dispenser delivers exact amounts at correctly spaced intervals, eliminating common causes of premature bearing failure. LubriCup is an ideal solution for a variety of situations, including:
- Lubricating bearings in hazardous or difficult-to-access locations
- Where human entry risks introducing contaminants
- Removing time-consuming and repetitive tasks
Chesterton Grease and LubriCup EM Series offers:
- Excellent corrosion protection
- High load-carrying ability
- Best-in-class water and chemical washout resistance
- QBT™ Quiet Bearing Technology
- Automatic grease dispensing
- Reduced lubricant consumption
One of the best Chesterton grease solutions to complement the LubriCup, try Chesterton 615 HTG. This high-performance, corrosion-inhibited, water-resistant grease with excellent intense pressure capabilities and exceptional water washout resistance. Ideal for demanding conditions of temperature, water, corrosion, and heavy loads.
Chesterton 615 High-Temperature Greases offers:
- NSF Registered, H2 – 615 HTG #2
- Outstanding extreme pressure and temperature characteristics
- Superior water resistance
- Excellent corrosion protection
- Exceptional shear resistance
- QBT™ Quiet Bearing Technology
The LubriCup and Chesterton 615 HTG Case Study
A client came to Chesterton with an issue with the vertical bearing of the hydra pulper failure due to severe conditions (water and chemicals). Lack of lubrication was also a significant concern due to the limited space available to access the bearing nipple and the subsequent safety issue for grease application, which often led to frequent equipment failure. Chesterton specialists recommended the Chesterton LubriCup EM Series with 615 HTG#2. Chesterton checked in with the client a year later, and they reported increased productivity and reliability without a bearing failure. Visit the website for more information on this case study.
Discover More Preventative and Repair Options with Chesterton®
Pulp & Paper plant operators being aware of common corrosion issues and taking preventative steps will vastly increase uptime while reducing maintenance costs. Contact a Chesterton® product expert, visit our website or email an enquiry to enquiries_apac@chesterton.com to discover a tailored solution to your needs.
This article was first featured in Paper Mart Directory.
