10 Questions You Should to Know about What Is Mild Steel

20 May.,2024

 

What is Mild Steel? Everything You Need to Know?

Mild steel comes with some excellent properties as you can weld and bend it conveniently according to your requirements. Therefore, it has a wide range of applications across different industries.

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Ease in machining and welding makes mild steel one of the most popular forms of steel available.

In this guide, we are going to break down EVERYTHING about mild steel in terms of:

So without further ado let’s get started.

Mild steel is a kind of steel that has low carbon content in it. Most of the carbon steels have a very small percentage of this element which goes up to 2.1%. Hence, this steel has more properties of iron in it.

Carbon content is going to vary immensely according to the requirements and application for which the steel is going to be used. Low carbon steels like mild or soft steel have a very low carbon content in them that ranges between 0.05% to 0.25%.

But there are different grades of mild steel as well and they all have a carbon content in them that ranges between 0.5% to 0.25% like we just mentioned. However, other elements are also added to improve various useful properties including wear resistivity, tensile strength, and corrosion resistivity.

And its surface hardness can be achieved through carburizing. It is a top choice for structural steel. It has a density of around 7.85 grams per cubic centimeter. For improving tensile strength more metal alloys are added to their composition.

It also improves the overall wear and corrosion resistivity as well. Alloying is primarily done with the use of silicon, molybdenum, chromium, copper, nickel, vanadium, and aluminum. Other impurities like sulfur and phosphorus are restricted in their proportions.

When you compare mild steel with higher carbon steel, it has higher tensile strength and it will not break. But it will deform or bend because there is not going to be any crystal deformation that occurs due to higher carbon content. Because of this, mild steel is highly useful in a variety of applications across different industries.

A uniform increase in the carbon content of steel can be achieved with the help of heat treatment. This treatment is a process that involves heating and then cooling metals. And there are various methods and techniques to achieve it. Non-ferrous and ferrous metals can both go through this treatment before they can be used.

With the increase in carbon content steel hardens but it loses its ductility. Consequently, the steel becomes brittle and it might fracture when you bend it by applying excessive load. But the manufacturing process of mild steel is similar to all other carbon steels.

However, higher carbon steel only has more carbon content in it and they also have different physical properties. These include higher strength and higher hardness value especially if you compare them with mild steel. With time, new processes and methods have been introduced and they are continuously evolving as well.

But primarily, there are three different steps involved in the process of making mild steel right out of pure iron.

●  Primary steelmaking

Primary steelmaking of mild steel

This step involves the mixing of iron ore with lime and coal and then it is heated inside a blast furnace that comes with a capacity ranging from 100 tons to 400 tons. Lime works as a flux as it develops a protective layer over the molten metal.

The modern methods of steelmaking involve BOS (Basic Oxygen Furnace) or EAF (Electric Arc Furnace). The BOS process involves blowing oxygen through the molten metal with the inclusion of scrap steel.

Doing this reduces the carbon content to around 1.5%. While the EAF process involves feeding of scrap steel through electric arcs of high power. And it significantly improves the overall quality of the resulting steel.

●  Secondary Steelmaking

Secondary steelmaking of mild steel

This step involves a further reduction of carbon content by adding various alloy elements. It is achieved by manipulating the furnace conditions by altering temperature and pressure. And to get the required type of mild steel various processes are used during this step. These include degassing, CAS-OB, Ladle injection, ladle furnace, and stirring.

●  Mild Steel Casting & Primary Forming

Casting and Primary Forming of Mild Steel

When the specified carbon continent is achieved and other elements have been added to enhance its physical properties according to the requirements, the molten metal is then poured out into the mold.

In this mold, the molten metal is given a shape and then allowed to cool down and solidify. At the end, when the steel has cooled down, cutting takes place into different shapes such as billets, blooms, and slabs to improve the surface quality, a hot rolling process is used.

●  Secondary Forming

Secondary Forming of mild steel

Though we have the complete mild steel in the previous step, usually, it is formed once again for improving its mechanical properties according to the requirements and applications. In this step, the mild steel gets its final properties and shape. The procedures that are used to finalize this step includes machining, shaping through cold rolling, coating, surface treatment, and tempering.

Here are some of the most common grades or types of mild steel.

●  EN 1.0301

This grade contains 0.1% of carbon, 0.4% of manganese, 0.4% or silicon. Apart from that, there are some small proportions of other elements as well, including aluminum, copper, chromium, nickel, molybdenum. The equivalent grades of this alloy steel here are AISI 1008, AISI C10, and AISI DC01. It is frequently used in furniture, appliances, and the automotive industry.

●   EN 1.1121

This mild steel grade features carbon content ranging from 0.08% to 0,13% and manganese content ranging from 0.3% to 0.6%. And its equivalent grade is AISI 1010. It has a wide range of applications in the automotive industry.

●   EB 1.0402

This mild steel grade has a carbon content ranging from 0.18% to 0.23%. Manganese content ranges from 0.3% to 0.6%. Its equivalent grades are AISI 1020, and AISI C22. It is a suitable choice for hydraulic parts and camshafts.

●   Chemical Properties

As we have mentioned above, mild steel features very low carbon content especially if you compare it with medium or high carbon steel. The carbon content doesn’t exceed 0.25% but according to some schools of thought carbon continents can reach up to 0.45% as well. 

However, mild steel composition might also have some other elements and metals in it. These include various proportions of cobalt, chromium, copper, sulfur, phosphorus, aluminum, nickel, molybdenum, and manganese. These elements equip the final product with different properties

For instance, chromium is useful in enhancing the corrosion resistivity of mild steel and it also increases its overall hardness. Chromium is essential because, in its purest form, mild steel can easily corrode as it has been oxidized.

With chromium, a layer of iron oxide doesn’t form on the steel. Instead with exposure a layer of chromium oxide develops and it is not going to fall off. Therefore this layer also prevents any further corrosion.

Similarly, chromium oxide also does the same thing. Mild steel might also be galvanized for better wear resistivity, excellent tensile strength, and heat resistivity.

Chemical CompositionIron98.81% to 99.26%Carbon0.14% to 0.20%Manganese0.60% to 0.90%Phosphorus<= 0.04%Sulfur<= 0.05%

●   Physical Properties

With this low carbon content, this metal becomes very machinable and easy to weld. Easy cutting and forming into various shapes without any proportional stresses is one of the primary features of this steel.

It also means that mild steel strength is not that much especially if you compare it with high carbon or medium carbon steel. Plus, mild steel density and mild steel weight are going to be on the lower side as well as compared to its higher carbon counterparts. The melting point of mild steel is also significantly lower than other carbon steels.

Mild steel has very impressive physical properties, and for that reason, it has been increasingly used in various industries. Mild steel is,

  • High strength to handle impacts.
  • High tensile strength.
  • Excellent weldability and ductility.
  • Magnetic metal because of the ferrite content in it.
  • Cold forming possibilities for excellent malleability.
  • Not the best option for heat treatment for improving physical properties.
  • Almost impossible to harden during quenching and eating.
  • Subject to corrosion if not treated with a proper coating.
  • More affordable as compared to other forms of steel.

Mild Steel Strength, Density & Melting Point

Mild steel is extremely strong as it has very low carbon content. It means that this metal has high resistivity against breakage. Even when it is cold, it’s quite malleable and therefore, it has high impact and tensile strength. Under high pressure, it will not break but will deform or bend. Mild steel density is around 0.248 pounds per cubic inch, and the melting point of mild steel is 2570F.

Mild Steel Mechanical & Electrical PropertiesHardness Brinell (Knoop, Rockwell B, & Vickers) 126 (145, 71, & 131)126 (145, 71, & 131)Ultimate Tensile Strength (Yield)63800 PSI (53700 PSI)Elongation @ Break (within 50mm)15%DuctilityHighMachinability78% (based on 100% machinability of AISI 1212 steelWeldabilityInstant welding (but not recommended when carburized or nitrided)Corrosion ResistanceHigh with alloyingAffordabilityCheaper than most steelsMagnetismYesCuttingFlame, disc, and plasma cuttingHardening/StrengtheningImpossible through quenching or heatingHeat ResistivityHigh (up to 540C/ 1000F)

Mild steel has been used across different industries for a variety of purposes. It is the most common form of metal that we see around our houses and workplaces.

●     Construction

There are some grades of mild steel that are called structural steels because they offer a tremendous amount of resistivity against loads and pressure. Mild steel also meets the wind and seismic requirements and it can resist corrosion and fire as well. Plus, it is far cheaper as compared to other forms of steel as well.

●     Machinery applications

In automobile manufacturing and machinery application, mild steel is frequently used. It works well with different coating requirements and cutting techniques. It also has excellent weldability and is an ideal choice for making panels and frames.

●     Poles and pipelines

Due to its maximum ductility, mild steel is a top choice for making pipelines and poles. Plus, it can also handle extreme weather conditions pretty well.

●     Cookware and cutlery

In the past, the chefs of the modern age loved to use stainless steel cutlery.

But that is changing quite rapidly as more and more of them have found mild steel cutlery far more advantageous.

With mild steel, the cutting equipment is easier to clean and be sharpened. It also has a higher temperature limit and will not stick to materials.

With competitive price and timely delivery, Nearyz Resources sincerely hope to be your supplier and partner.

●     Fencing

This type of steel can be shaped into anything pretty easily and for that reason, it is a top choice for fencing. Mild steel also has a visual appeal as it looks pretty eye-catching.

Product Forms Available of Mild Steel

Mild steel is available in different product forms. Apart from the sheet, it is available in box section channel, angle, flat, square, hexagon, round, tube, T-section, pipe, mesh, threaded bar, telescopic tube, and half-round molds.

It means that it can be used in a range of different applications according to the needs and requirements.

As there is a wide range of case uses and applications of mild steel there are different surface finishes available as well. All these processes are equally effective and anyone of them can be used based on aesthetics and usage requirements.

Apart from that, mild steel is known for rusting and corrosion due to the oxidation process and it is very much similar to wrought iron.

Therefore, there are some surface finishes to prevent the oxidation process and keep the metal safe from corrosion and rusting.

– Priming

It is one of the surface finishes that involves painting the metal with paint containing zinc phosphate. This finish works as an active rust-resistant coating. The zinc phosphate compound tends to disrupt the formation of anodes on the surface of the metal.

This is achieved by hydrolyzing water to start producing zinc and phosphate ions. Phosphate ions act as anodic while zinc ions work as cathodic inhibitors. But for the best results, this paint has to be applied with a thickness in a layer that measures to be around 125 microns.

It can be achieved by applying it to different layers with the help of a roller. But keep in mind, this is only a suitable finish for indoor use and not for extreme conditions.

– Galvanizing

This process only involves coating the steel with a layer of zinc.

This can be done by dipping that steel into molten zinc. Zinc will start to react with steel when it cools down and forms zinc carbonate. After this process, it is called galvanized steel.

This layer will protect the steel in two different ways,

  • The base metal underneath the layer is not exposed to the atmosphere and its different elements.
  • The zinc coating of galvanized steel behaves as a sacrificial safety layer. It means that zinc will start corroding first because it has a greater electronegativity than the steel that it is protecting underneath.

Galvanizing is one of the best surface finishes that will work for the steel that is going to be used in outdoor areas, as it can handle harsh conditions pretty well. With this surface finish, the metal can handle rains, sun, and winds pretty well

– Intumescent Coating

These coatings are pretty much like paints and they are inert at cold temperatures but they work as insulation due to a complex chemical reaction at temperatures around 200C to 250C. These temperatures don’t influence steel. The reaction causes the coating to swell and expand the layer of low conductivity.

There are two different types of these intumescent coatings: thick and thin films. Thick films are developed for hydrocarbon and off-shore industries to be used in buildings. On the other hand, thin films are water or solvent-based layers that are useful for building fires. These films are very useful to make mild steel fire-resistant.

Pros & Cons of Using Mild Steel

Pros:

  • Mild steel is extremely light as compared to other forms of steel.
  • It is pretty cheap as well in comparison to other carbon steels.
  • Mild steel is more malleable and ductile than other steels.
  • It is more convenient to recycle mild steel as compared to other forms of steel.
  • It can be used for a variety of purposes and is highly versatile.

Cons:

  • One cannot heat treat mild steel.
  • It doesn’t handle high-stress applications and beds or deforms easily.

Frequently Asked Questions

Can you harden mild steel?

Yes, you can harden mild steel if you increase the carbon content in it.

But due to the oxidation process hardening becomes a tough task as the steel has been processed to reduce its carbon content.

Mild steel is alloy steel or a pure metal?

Mild steel is not a pure metal. It has large iron content in it with other elements including carbon, nickel, chromium, aluminum, etc. In the purest form, it is iron.

How is mild steel different from high carbon steel and medium carbon steel?

Mild steel has a very low carob continent in it as compared to medium and high carbon steels. It has a carbon content that ranges from 0.5% to 0.25%. Whereas, high and mediums carbon steels have higher carbon content.

Is mild steel stronger than stainless steel?

The strength of metal has different meanings in different contexts. For instance, if you compare mild steel with stainless steel than mild steel is much more ductile and malleable than stainless steel. It doesn’t break easily but you can bend and deform it.

On the other hand, stainless steel is much more brittle due to the higher carbon content in it. It’s more prone to breakage at high pressures than mild steel but it has high corrosion resistivity as well. And both these properties have different uses.

Final thoughts

Due to its high ductility and malleability, you need to consider using mild steel for various applications. Mild steel is quite frequently used across different industries due to its physical properties. It has high machinability and weldability and is a top choice for various manufacturing industries.

Mild steel has much lower carbon content in it and can be easily treated for wear and corrosion resistivity by the addition of different alloys. Due to its easy handling mild steel is one of the most versatile metals to be used for a variety of applications.

METALLURGY 101 - Different Steel Definded -

Post by Scratch » Thu Feb 17, 2011 12:28 pm

I started this thread on another forum and I think it would be good to have on this forum also. I know when I first started, I didn?t know the difference between HR and CR steel and didn?t want to look like an idiot so I did some research. If you have any input, or info on any other common types of metals, post it up here and I?ll keep editing this first post so the good stuff is at the top of the thread.

MILD STEEL

-not aluminum, not copper, not stainless, just regular old magnetic, steel that'll rust.

A-36 STEEL

- Is a standard steel alloy which is a common structural steel used in the United States. * Plate * I-beam * Pipe * Bar * Sheet are some of the forms it is made in. Steel seems to have an inconsistent numbering scheme. Sometimes it's as above, where the number is somewhat descriptive. Other times I think it's just a spec number. A-36 specifies minimum yield strength, not hardness. So it could have more carbon than mild, if that's what was in the soup when they made it.

AR STEEL

- Abrasion Resistant Steel Plate (AR Steel Plate) with superior forming, welding and wear characteristics. This steel plate, with it's high Brinell Hardness ( BHN ) ratings, is particularly suited to the mining equipment, earth moving equipment, ore and aggregate processing, road building equipment manufacturing and fabrication industries, and rifle range silhouette targets, target backstops and bullet trap applications. Hardening agents such as carbon and manganese are used in the make-up of AR Steel Plate. Standard AR steel plate grades are AR200, AR400, AR500, and AR600 with the higher the number, representing the higher BHN rating.

COLD ROLLED STEEL

- formed cold using pressure to force the steel down to the size wanted. It has a tighter grain, therefore Harder than HOT ROLLED STEEL, and is good for machining. It also has much closer tolerances than hot rolled. Hot rolled rounds are not exactly round, cold rolled is. If it matters use cold, if it doesn't, use hot & save the money.

HOT ROLLED STEEL

- steel created and formed using a process that puts a layer of "mill-scale" on the surface of the steel, that among other things, acts as a pretty good rust preventative. It is worked into shape by roll forging. Shaping at a red temperature so it is easier to shape. and less pressure is needed. Also not quite as hard as COLD ROLLED STEEL.

PICKLED AND OILED

- (P&O steel) Hot rolled steel that is oiled as a rust preventative that is much easier to remove than mill scale. Pickling is a treatment of metallic surfaces in order to remove impurities, stains, rust or scale with a solution called pickle liquor, containing strong mineral acids, before subsequent processing, such as extrusion, rolling, painting, galvanizing or plating with tin or chromium. The two acids commonly used are hydrochloric acid and sulphuric acid. Pickling liquor may be a combination of acids and may also contain nitric or hydrofluoric acids.
Oiling is the rust treatment.

SHEET STEEL

- any of the steel formed into big flat sheets like sheets of plywood. Sheet steel is rated for thickness. This is by the gauge number rather than the fractional thickness.

PLATE STEEL

- Plate steel is rated for thickness. This is by the fractional thickness rather
than the gauge number. Plate starts at 3/16"

IRON

- Is too soft to hold an edge or shape in its pure form. It is combined with other materials to form other materials that are better worked.

CAST IRON

- It is an iron alloys containing 1.8?4.5% carbon. Cast iron usually is made into specified shapes, called castings, for direct use or for processing by machining, heat treating, or assembly. In special cases it may be forged or rolled moderately.

WROUGHT IRON

- Wrought Iron was created from bloom steel. It came out of the blooms as a lump of molten steel. This blob was hammered into shape to refine it and drive out the impurities. It was wrought, hence the name wrought iron. It has a grain to it almost like wood. It was much easier to forge weld than modern hot rolled.

DAMASCUS STEEL

- Damascus got its name from the Damascus region in the middle east. Not because it was made there, but because it was a trading center and was sold there. The proper modern name is pattern welded steel. Usually layers of a high carbon steel are stacked with a lower carbon steel and forge welded together. After they are welded various things can be done to the billet to create a pattern. (twists, holes drilled, slots cut etc) When you then grind a knife blade on an angle it reveals different layers and the pattern. You also need to etch the steel is some type of acid so that the variations in metal show up. The high carbon doesn't etch as easily as the low, so you get purty purty patterns. I recommend a book called, The Pattern Welded Blade, by Jim Hrisoulas. What I just wrote is the most basic explanation. He covers it well and shows how to create various patterns. It is a great book by a true master of the craft.

GALVANIZED STEEL

- is the process of coating iron or steel with a thin zinc layer, by passing the steel through a molten bath of zinc at a temperature of around 860 ?F (460 ?C). When exposed to the atmosphere, pure zinc reacts with oxygen to form zinc oxide, which further reacts with carbon dioxide to form zinc carbonate, a dull grey, fairly strong material that stops further corrosion in many circumstances, protecting the steel below from the elements. This known as Hot dip, there is a Cold dip which doesn't give as strong bonding or protection but is a cheaper process.

TOOL STEEL

-Any of various steels capable of being hardened sufficiently so as to be a suitable material for making cutting tools. Contains materials that make it a good performer for cutting, and shaping other materials. Also called High speed steel.

STAINLESS STEEL

- Any of various steels alloyed with at least 10 percent chromium and sometimes containing other elements and that are resistant to corrosion or rusting associated with exposure to water and moist air.

I think I'm the oldest 10 year old boy on the forum...

For more information, please visit What Is Mild Steel.