How CRGO steel is manufactured

Here is a short summary of the main steps and why they are important:

Key Takeaways

• CRGO steel is made by following careful steps. These steps help make its magnetic properties better. This makes it great for use in electrical devices. Using good raw materials is very important. Pure iron ore and silicon are used to get better results in electrical work. The cold rolling process lines up the steel’s grain structure. This makes its magnetic power stronger and helps save energy. Annealing is a step that brings back magnetic properties. It also changes the tiny structure inside the steel. This helps lower power loss in the steel. Cutting the steel with care and testing it well is important. This makes sure CRGO steel laminations are high quality for transformers and motors.

CRGO Steel Manufacturing Process

Raw Material Selection

Importance of High-Quality Raw Materials

To make crgo steel, you must pick good raw materials. You need iron ore and silicon that are very pure. Pure materials help the steel work better in electrical devices. If the materials are clean, the steel has better resistivity and magnetic power. If there are impurities, magnetic domains cannot move well. This makes the steel less useful for its job. Adding more silicon helps resistivity and lowers energy loss. But, it also makes the steel harder to shape and work with.

Here is a table showing the typical chemical composition for electrical steels:

Sheraxin's Approach to Material Selection

Sheraxin uses strict rules when picking raw materials. They know how to find the best silicon steel. This careful way helps Sheraxin make crgo steel that is always good. Using pure materials means the steel works well in advanced electrical tools.

Electric Arc Furnace Steelmaking

Advanced Steelmaking Techniques

After picking the best materials, you melt them. The electric arc furnace uses strong electric arcs to melt the mix. These arcs can get as hot as 3,000°C. The furnace lets you change the steel’s mix while it melts. You can change the current, voltage, and power to get the right mix. This step takes out bad stuff and makes the steel even and high quality.

Sheraxin's Steelmaking and Refining Capabilities

Sheraxin uses modern furnaces and refining machines. These tools give you many benefits:

• You can make more or less steel as needed.

• You can use different raw materials, like scrap or direct reduced iron.

• You get steel with fewer bad things in it, which is great for crgo steel.

Sheraxin makes a lot of crgo steel and sells it worldwide. China, where Sheraxin works, makes over half of the world’s crgo steel. This means you can count on Sheraxin for steady supply and great results.

Cold Rolling and Grain Orientation

Cold Rolling Process

You begin with high-silicon steel alloy made into ingots. These ingots are hot-rolled into thin strips. After hot rolling, the strips are annealed in a special atmosphere. This step helps make a unique texture in the steel. Next, the strips are cold-rolled at room temperature. Cold rolling makes the strips thinner, between 0.1 mm and 0.5 mm. This step also makes the grain structure better and the steel stronger.

Here are the main steps in the cold rolling process for crgo steel:

1. Casting: High-silicon steel alloy is cast into ingots.

2. Hot Rolling: The ingots are hot-rolled into thin strips.

3. Annealing: The strips are annealed to form a special grain texture.

4. Cold Rolling: The strips are cold-rolled to the final thickness.

Cold rolling forms a Goss texture. This texture lines up the grains with the rolling direction. Lined-up grains help magnetic properties and lower core losses. The steel has higher permeability and works better in electrical uses.

Grain Orientation Techniques

Grain orientation techniques help grains in crgo steel line up with the magnetic flux path. This makes it easier to magnetize and lowers core losses. Adding silicon helps grains point in the easy magnetization direction. When tension is used, magnetization lines up with the tension. This makes magnetization easier. If pressure is used, magnetization goes sideways to the pressure. This makes magnetization harder.

Grain orientation in electrical steel lets magnetic domains line up with the magnetic field. This lowers domain wall pinning and hysteresis losses. The steel works better in transformers and other electrical devices. Good grain alignment is important for both magnetic and mechanical properties.

Tip: Grain-oriented steel is best for transformer cores. It saves energy and helps transformers work better.

Annealing, Decarburization, and Coating

Annealing for Grain Structure

You heat crgo steel to change its grain structure. This helps the steel work better with magnets. Annealing has three main steps. First, you heat the steel to between 550°C and 700°C. Next, you keep the steel at this temperature for a while. Last, you let the steel cool down slowly.

During annealing, the steel goes through different stages. In the recovery stage, you heat the steel below the recrystallization point. This step lowers stress and core loss. In the recrystallization stage, you heat the steel above the recrystallization temperature. New grains form, and grains get bigger. In the grain growth stage, you keep the steel hot so grains can grow more.

If you anneal at lower temperatures, the steel changes less. But core loss still drops. At higher temperatures, new grains form. The steel’s magnetic properties get even better. Annealing also brings back magnetic properties and changes the microstructure. This helps lower power losses.

Decarburization Process

Decarburization takes carbon out of the steel. You heat the steel to high temperatures, usually above 700°C. Carbon reacts with gases like oxygen or hydrogen and leaves the steel. This step makes the steel softer and easier to shape. It also helps the steel work better with magnets and lowers core losses. When you cut carbon to less than 0.06%, you stop aging and reduce eddy currents. This change raises electrical resistivity and helps transformers work better.

Decarburization means removing carbon from the steel’s surface layer. It happens when high carbon steel is heated in a carbon dioxide atmosphere. The process uses reversible reactions to lower carbon content.

Insulating Coating Application

After annealing and decarburization, you put a thin insulating coating on the steel. The coating is usually 2 to 5 micrometers thick. It helps lower eddy current losses and keeps steel layers apart. You can pick different coatings:

The coating adds tensile stress, which makes magnetic domains smaller and boosts performance. It protects the steel from rust and helps it last longer. The coating keeps the steel strong and reliable in transformer cores. You get less noise, lower energy loss, and better durability.

• The insulating coating adds helpful tensile stress and makes magnetic domains smaller, which improves performance.

• It helps the steel resist rust and stay strong.

• The coating keeps steel pieces apart, lowers eddy current loss, and makes the steel work better.

Cutting and Quality Control

Precision Cutting of Laminations

You must cut CRGO steel laminations very carefully. This helps you get the right shapes and sizes for transformer cores and motor parts. First, you check the steel coils to see if they are good. You look at their size and surface. After checking, you cut big coils into thin strips. You need to be careful so you do not waste steel. Then, you use fast presses or laser cutters to make special shapes. These shapes can be E, I, or L forms.

Here is how the cutting process goes:

1. You check CRGO steel coils for quality and size.

2. You cut the coils into thin strips for laminations.

3. You use a punch or laser cutter to make the shapes you need.

How you cut the steel changes its magnetic properties and accuracy. Laser cutting can make a hot area that hurts magnetic properties. Losses can go up by more than 100% compared to mechanical cutting. Mechanical cutting can also cause stress and bend the edges. This makes magnetic performance worse. You need to pick the best cutting method to keep the steel’s magnetic properties strong.

Final Testing and Inspection

You must test and check each lamination before sending it out. These checks make sure the steel meets tough rules for electrical and size properties. You use different tests:

You also check thickness, width, and core loss numbers. Thickness can be from 0.18 mm to 0.35 mm. Width can be from 50 mm to 1050 mm. Core loss must be low, with a top value of 0.85 W/Kg for 0.23 mm thickness. Lamination factor should be 97.5% for the best quality.

Tip: Careful cutting and testing help you get CRGO steel laminations that work well in transformers and motors. You keep losses low and efficiency high.

Every step in making crgo steel changes how it works. Hot rolling, silicon alloy coating, and annealing all help the steel work better. These steps make the steel good for transformers and motors. But there can be problems. Rolling mistakes, bad annealing, or coating issues can hurt the steel.

Certified products follow strict rules. They help your devices work well and last longer.

FAQ

What does CRGO stand for?

CRGO means Cold Rolled Grain Oriented steel. This steel is used in electrical transformers. The grains are lined up to help magnetic flux move. This makes energy loss lower.

Why do you add silicon to CRGO steel?

Silicon is added to make the steel resist electricity better. This helps lower core losses and makes magnetic properties stronger. Silicon also makes the steel harder, so you must be careful with it.

How does grain orientation help transformers?

Grain orientation lines up the grains with the magnetic field. This gives better magnetic performance and less energy loss. Transformers work more efficiently because of this.

Can you recycle CRGO steel?

Yes, CRGO steel can be recycled. You melt it and use it to make new steel things. Recycling saves both resources and energy.

What is the typical thickness of CRGO steel sheets?

CRGO steel sheets are usually 0.18 mm to 0.35 mm thick. Thinner sheets help lower core losses in transformers.