Boiler is an important device used to produce heat for heating or steam generation. However, during use, the boiler may encounter corrosion, making the equipment inefficient or even damaged. The causes of boiler corrosion are varied. Here are some common causes.

Common causes of boiler corrosion

There are many different causes of boiler corrosion. Here are some common causes of boiler corrosion.

1 – pH of water is not up to standard

Water with high or low pH can cause corrosion of metal surfaces in boilers. Water with a high pH, ​​i.e. alkaline, is strongly corrosive and can corrode metallic materials in the boiler. Water with a low pH, i.e. acidic, is also corrosive and can cause corrosion of metallic materials in the boiler.

If the pH of the boiler water is unstable or too high or too low, it can cause corrosion and shorten the boiler’s life. Therefore, to avoid corrosion by the pH of the water, it is necessary to use chemical products to adjust the pH of the water in the boiler, and periodically check and balance the pH of the water.

ăn mòn lò hơi
Water pH is one of the main causes of boiler corrosion

2 – Concentration of gases, metal ions and dissolved ions in water

Gases, metal ions and dissolved ions can all cause boiler corrosion.

Gases such as oxygen and evaporated water can cause metal surface corrosion in boilers by creating new chemical compounds on the metal surface.

Metal ions can be oxidized or reduced in the boiler, and this can cause corrosion. Metals such as iron and copper can be easily oxidized and form metal oxides, while aluminum and zinc can be reduced to hydrogen gas. These compounds can all cause corrosion of metal surfaces in boilers.

sơ đồ nguyên tắc ăn mòn oxy
Diagram showing the corrosion principle of Oxygen

Dissolved ions such as chloride and sulfate can attack and corrode metal surfaces in boilers. If there is a large amount of dissolved ions in the boiler water, they can create a strong corrosive environment and cause metal surface wear.


3 – Due to boiler scale

Scale can reduce boiler heat transfer efficiency, increase boiler internal pressure and cause metal surface corrosion. If not removed in time, scale can create gaps in the metal surface of the boiler, and these gaps can allow water and corrosive substances to easily penetrate and attack the surface. of metal.

Therefore, to minimize the impact of scale on boilers, scale treatment measures are often applied, including the use of separators, regular cleaning and the use of water treatment systems to minimize sedimentation of water.

cáu cặn ăn mòn lò hơi
Scale is also the cause of boiler corrosion

4 – Other mechanical factors

Mechanical and physical factors such as water flow velocity, temperature difference, etc. are also one of the common causes of boiler corrosion.

  • Water flow rate:

If the flow is too fast, it can cause trace corrosion in areas of lower conductivity. On the other hand, if the flow is too slow, it can cause abrasive-type corrosion, which affects the metal surface in the boiler.

  • Temperature difference:

The temperature difference can lead to the formation of cracks in the metal surface in the boiler. These cracks can be a concentration of corrosive substances and can lead to metal-to-metal contact, causing corrosion.

  • Pressure between boiler metals

As the pressure increases, the temperature and temperature difference between the metal materials in the boiler also increase, causing the expansion and contraction of the materials. This expansion and contraction can lead to intermolecular jostling and cause cracks and damage to the metal surface, leading to the risk of corrosion.

  • Device downtime

Device downtime is the amount of time the device is idle or unused. If the equipment downtime is too long, corrosive substances can build up and cause corrosion inside the equipment.

nguyên nhân ăn mòn lò hơi
Mechanical factors that can cause boiler corrosion


Negative effects of boiler corrosion

Corrosion is a very common problem in industrial boiler systems. Boiler corrosion can be very serious and cause many unintended consequences to the system.

One of the biggest harms of boiler corrosion is reduced equipment durability. Corrosion of system parts can cause serious breakdowns and increase repair costs.

In addition, corrosion can reduce system performance. As parts corrode, they can become damaged, resulting in reduced performance and increased repair costs. This can reduce the life of the system and increase operating costs.

tác hại ăn mòn lò hơi
Boiler corrosion can cause cracking

If corroded parts are not periodically inspected and replaced, corrosion can also cause dangerous problems. Surfaces can crack, and the high temperature in the furnace promotes very rapid corrosion. As a result, water or steam leaks may result, posing a hazard to the operator.

Therefore, to minimize the harmful effects of boiler corrosion, periodic maintenance and inspection of system components are very important. The use of anti-corrosion materials and anti-corrosion products is also an effective way to reduce the harmful effects of corrosion and keep the boiler system in good working order.

Some methods to prevent boiler corrosion

Various methods of boiler corrosion prevention are available, ranging from the use of anti-corrosion materials, to monitoring and control devices.

One of the most common methods of anti-corrosion is the use of corrosion-resistant materials such as Inconel or Monel alloys. These materials have high corrosion resistance properties, which can protect the boiler from corrosive damage.

In addition, control devices are also important to prevent boiler corrosion. pH sensors, which monitor the variation of water in the boiler to help control corrosion.

Moreover, the use of chemical maintenance is also an effective method to prevent corrosion. The way not only inhibits the corrosion process, but also prevents the boiler scale disease.

One of the reputable boiler maintenance chemical suppliers is Long Truong Vu. With more than 20 years of experience, the company has become a reliable partner of many businesses.

hóa chất bảo trì lò hơi
Using chemicals is one of the effective methods to prevent boiler corrosion

The above are some common causes of boiler corrosion. Understanding this cause is extremely important so that effective preventive and anti-corrosion measures can be put in place.