Cast steel is one of the major metals in our day-to-day lives, and there are a large number of objects that are manufactured of cast steel. Therefore, it is typical for a welder to run across a circumstance in his work routine in which he is required to weld cast steel.

I am going to go through the process of welding cast steel in great detail here in this blog. And could you please explain why the cast steel welds that you have been using keep cracking open? now let’s get started.

Can You Weld Cast Steel?

Similar to many other metals, Cast steel can be welded. The only difference is that when you weld cast steel, sometimes the weld will crack.

Because of this, it is very important to choose the right welding method and the right electrode type. We will discuss this in more detail later in this article.

Things You Need to Consider Before Welding Cast Steel

Before attempting your first weld on cast steel, there are a few things to keep in mind.

1. Size of the piece you are welding
2. Controlling the temperature of the weld pool
3. Dealing with the distortion of the piece during welding
4. Service age of the working piece
5. Environmental conditions

1. Smaller Pieces are Easy to Weld

When compared to huge cast steel pieces, smaller ones are significantly simpler to weld. There is less chance of fracture or distortion if you are welding a small piece.

When welding small parts together, you need to pay close attention to ensure those small tiny cracks that may remain even after welding.

2. Controlling the Temperature of Weld-Pool is the Key

When it comes to welding, cast steel is more prone to cracking. Because of this, you need to take extra precautions to prevent the steel from cracking by not allowing the weld pool to cool too rapidly.

This isn’t usually necessary if the casting is made of low-carbon steel or contains manganese, both of which make the material considerably tougher than standard cast steel.

But still, It is an important aspect to consider before starting to weld cast steel.

3. You Need to Learn How to Deal with Distortion During Welding

Cast steel is known for being hard to weld without causing a lot of distortion. cast steels are much more likely to bend than other metals, and this becomes more obvious as the amount of carbon in them goes up.

When welding cast steel, you need to be extra careful that the surrounding temperatures won’t cause problems before, during, or after the process.

4. Service Age of the Workpiece Matters a Lot

The service age of any metal is very important and it directly affects the melting point and strength of the material.

So while working with cast steel you should definitely consider the age of the workpiece that you are welding.

5. Cast Steel Welding Requires Special Environment

The age of the service and the environment in which the cast welding is performed both affect the weld quality.

It’s important to know the temperature range in which your alloy works best since extremes in either direction could make things harder and lead to unexpected results.

Not only that, but Welding is also very hard to do with cast steel because of environmental factors like moisture and humidity.

How to Tell Whether It’s Cast Steel or Cast Iron?

There are 3 ways through with you can identify the difference between cast iron and cast steel.

1. Look at the grain structure
2. Colors of the sparks when grinding
3. Drill and see the chip’s structure

1. Look at the Grain Structure

If the part is broken, looking at the grain structure will help differentiate between cast iron and cast steel. The grain struct of cast iron is a dull and dark type, while the cast steel grain structure is more shiny light grey color.

2. Color of Sparks When Grinding

Grind the part and see what the color of the spark is. In cast iron, the spark color tends to be brightest at the end of the spark stream away from the grinder.

While in cast steel the orange spark develops right at the grinding wheel and then they extend out.

3. Drill Chip’s Structure and Shape

Drill your workpiece and see what the structure of the chip is. In the case of cast iron, the chips are more like refined small particles like lead. while in the case of steel the chips are more like shiny long spiral chips.

How to Weld Cast Steel?

The key to welding cast steel is to keep the metal from expanding and contracting too much while welding and after welding. If you don’t do it, the metal will always break on you.

If you want to succeed, you must preheat the cast steel and let it cool gradually. Depending on the welding procedure you want to employ, you need pre-heat the cast steel to a certain temperature.

In the following paragraphs, I will be discussing in more detail how you can weld cast steel.

1. Preparing Cast Steel for Welding

All metals, including cast steel, need to be cleaned and prepared before they can be welded. If the surface of your cast steel is dirty, you can’t expect good welds to form.

Some of these pollutants could be very bad for your health if they are burned and turn into fumes during welding.

To get the rust off the surface of your steel, you have to work very hard. Rust is a common problem with mild steel, which can make it hard to make a good weld.

The most common problem caused by rust is porosity, which means that there are a lot of small holes in your welds. Porosity can make a weld connection very weak.

There a 2 methods which you can use to clean your cast steel before welding:

1. Mechanical Method
2. Chemical Method

The method you choose will depend on the type of metal, its condition, the way you want to weld it, and the tools you have on hand.

Mechanical Method

When you clean cast steel mechanically, you scrape, brush, or grind the surface to remove dirt. I typically only clean steel parts by hand (without the aid of power tools) when they are really tiny since power tools are a bit too quick. I suggest using a very strong wire brush if you decide to manually clean steel.

Make sure the metal in your wire brush or the metal on the attachment you want to utilize on your power tool is the same metal you’re going to weld when cleaning.

For instance, use a steel wire brush or grinder to clean a piece of steel rather than one made of brass or another metal. If not, there is a chance that the metal will get contaminated with another metal.

Aluminum may be cleaned with a stainless steel wire brush without issue.

Also In many welding facilities, particularly those that weld big pieces, tools driven by electricity or pressured air have become the norm for cleaning steel. Angle grinders are the most used power instruments for cleaning steel.

Chemical Method

As you may have guessed, chemical cleaning is a process that makes use of harsh chemicals to clean steel. Please handle the materials with the greatest care if you want to clean them with chemicals since I’m talking about some very abrasive chemicals here.

Here are a few substances that you may wish to take into account when cleaning steel.

• Acetone
• Alcohol
• Acid

Be aware: Make sure that no spark or flame ever comes into touch with the solvent or its vapors while cleaning steel and other metals before welding. Almost all solvents are very combustible.

2. Selecting the Welding Method for Cast Steel

Any of the modern welding processes may be used to weld steel, although I advise sticking to only:

• Stick Welding
• MIG Welding
• TIG Welding

Here is a brief overview of some important steel welding details for each of those procedures.

Stick Welding

Stick welding is one of the most effective methods for welding cast steel. It’s portable, which is useful when you need to weld a large piece of steel that you can’t readily move, and it’s flexible and economical in comparison to other welding techniques.

You can stick weld nearly any piece of steel with a thickness of 1/8 inch or more.

MIG Welding

It is possible to MIG weld cast steel in any orientation, which is one of the reasons why MIG is the preferred method for cast steel welding projects.

With MIG welding, you may get a very smooth weld, and you can prevent most of the spatter and waste that might occur with stick welding.

As long as you have a strong MIG machine, you can even weld incredibly thin pieces of steel using MIG.

TIG Welding

Similar to MIG welding, TIG may be used to weld cast steel of different thicknesses. TIG also provides a very clear view of the weld area since it generates so little smoke and slag (waste).

If you do not utilize the proper filler rod, the quality of your weld will be severely compromised.

If you pick TIG for your steel welding projects, ensure that your equipment is properly configured. Make sure to use charts that will assist you in determining the appropriate amperage, shielding gas flow rate, and polarity for tig welding steel.

Related Information: MIGvs TIG Welding: Which one is Better?

3. Performing Stick Welding on Cast Steel

For the purpose of demonstration and understanding, I will be assuming that you have selected stick welding to weld cast steel.

Safety Checklist before Stick Welding

• Welding helmet with a filter ranging from #10 to #14.
• Long pants made of leather, wool, or cotton; jacket made of leather.
• Heavy-duty gloves designed for use in welding.
• Eye protection glasses.
• Hat.
• Shoes or boots made of leather.
• Proper Ventilation.

Required Equipment for Cast Steel Stick Welding

1. A grinder for cleaning
2. An oxyacetylene torch to preheat the workpiece
3. Temperature indicating crayon to measure the temperature of the piece
4. Standard Stick welding setup
5. 7018 Stick welding electrodes ( Esab OK 48.15 )

You can use your thermal phone camera to measure temperature when preheating your workpiece.

Choosing the Right Electrode Type is the Key to Success

Probably the most important thing to do when welding cast steel is to choose the right type of electrode. I want you to pay extra attention as you choose the electrode rod for welding cast steel.

Because if you don’t choose the right type of electrode, the quality of the weld won’t be good, and the weld might also crack as soon as the weld pool cools.

Here are a few of the tips that might help you find the right electrode type for cast steel welding:

• Always use the E7018 electrode.
• Make sure to use a low hydrogen content electrode.
• The coating type should be basic.
• It’s better to use an electrode made of “Carbon Manganese” (Not necessary).
• Avoid cast iron rods at all cost

Esab OK 48.15 is one of the many electrodes that fulfill all of the above-mentioned requirements.

The Secret Behind Cast Steel Welding is Preheating the Metal

This is the most important part of this whole article. This step is the one that most welders miss when welding a cast steel workpiece.

Controlling the metal’s expansion and contraction both during and after the welding process is essential for successfully welding cast steel.

The weld will break if you do not do it. If you want to succeed, you must pre-heat the cast steel and let it cool gradually.

When utilizing stick welding, the workpiece must be preheated to a temperature ranging from 150 to 300 degrees Celsius.

To determine the temperature of your cast steel, use a temperature-indicating crayon. Simply mark the metal with the crayon, start the preheating process, and when the metal reaches the temperature specified on the crayon, the mark will melt.

So, if you have a crayon that can mark metal at 300 degrees Fahrenheit, you may mark the metal, heat it with a torch, and then check to see whether the mark melts off to see if the metal has hit 400 degrees.

Selecting the Right Current Type and Amperage Settings

Set the amperage on your stick welding equipment to the appropriate value, and set it to direct current positive (DC+).

For this sort of job, always use the smallest electrode you can get away with in order to keep the welding heat as low as possible.

I advise, when stick welding cast steel wherever possible using 332-inch electrodes.

Lesser heat equals less expansion, which means a lower danger of cracking.

Why I Didn’t Choose MIG Welding for Cast Steel?

Even though it is possible to MIG weld cast steel, I don’t recommend it. Because it requires more skill and it is very difficult to control the temperature of the weld pool which is very crucial in cast steel welding.

Compared to MIG welding, TIG welding is faster and doesn’t have as many problems, like spatter, which can make the finished product look sloppy.

I know Cast steel is hard to weld with a TIG because it needs more precision to avoid warping and cracking. However, if you give it a try, you’ll see why I am preferring TIG over MIG.

Tips for Producing High-Quality Welds When Working with Cast Steel.

Here are few of the important tips that will help you increase your welds quality when working with cast steel:

• To keep your cast steel cold and motionless while welding, use a sandbag or a similar instrument.
• Instead of depending only on clamps, hold components together while you weld.
• Warm up your material to reduce the possibility of fracturing.
• Remember to replace plain steel filler material with stainless steel to avoid deformation and enhance the final quality.
• Avoid allowing your cast steel to get too hot by sheltering it or using water to cool it.
• Remember that bigger pieces of cloth will take longer to heat up and cool down.
• Use stick welding rather than arc welding to reduce the risk of cracking.
• Always refer to the welding manual for the particular cast steel product you are using.
• Use an electrode that is suitable for the level of current you are utilising.

How to Weld Cracked Cast Steel?

Same as above we will be using stick welding process for welding cracked cast steel as well.

Things You Need to Weld the Cracked Cast Steel

• A standard stick welding setup:
• Torch made with oxyacetylene
• electrodes for stick welding manufactured specifically for cast steel
• a drill with a drill bit for cast steel drilling
• A grinder (optional)

Step by Step Process for Welding Carcked Cast Steel

First, you’ll need to prepare the piece by drilling a tiny hole at the end of each crack and maybe even a fraction of an inch beyond it.

Second, using the oxyacetylene torch, bring the cast steel to a temperature of 400 to 1,000 degrees Fahrenheit in the area where you’ll be welding.

Third, switch to direct current electrode positive (DC+) and adjust the amperage on your stick welding equipment to the number recommended for the electrode you want to use.

Fourth, Use an arc that is somewhat longer than the arc used to stick weld steel.

Fifth, begin welding on the crack about a half an inch below the hole you bored in Step 1; return to it and weld a half an inch beyond it while retracing your steps.

Sixth: Return to the hole from Step 5; repeat for any additional holes; weld a bead about 112 inches long in the direction of the centre of the fracture.

Seventh, go back and forth in this manner until the whole crack is filled.

If you want the best results, wait until the first section of the weld has cooled completely before moving on to the second. Cleaning the item after each weld is also recommended.

Spending the extra effort on these procedures is worthwhile if you care about getting a reliable weld.

Wrapping it Up

Controlling the temperature of your weld pool is the sole challenge involved in welding cast steel; the process itself is rather straightforward. If you are unable to maintain temperature control, the weld may fracture, which will lead to a reduction in strength. I really hope that the information that was provided for you will help you find a solution to your issue. I also hope that you enjoyed reading this essay.