Alloy Steel Vs Stainless Steel

Alloy Steel Vs Stainless Steel - The Ultimate Guide

Before choosing alloy steel or stainless steel; you should understand properties, chemical composition and applications, among other vital aspects. So, if you want to have an in-depth knowledge on these engineering materials, read this guide.

What Is Alloy Steel?

It refers to steel containing different chemical elements totaling amounts ranging from 1.0% to 50% by weight. The essence of alloying steel is to enhance its mechanical properties and make it suitable for different applications.

What Is Stainless Steel

It is an alloy of iron that hardly rust irrespective of the conditions it is exposed to. Stainless steel contains chromium, nickel, and other elements such as carbon and non-metals to attain the desired properties. It is wholly and infinitely recyclable with incredible tensile strength of about 621 MPa or 90 KSI.

What Is Stainless Steel
Alloying Element In Alloy Steel Vs. Stainless Steel

Alloying Element In Alloy Steel Vs. Stainless Steel

The essence of alloying elements is to alter chemical and mechanical properties and enhance strength of metals through their effect on the matrix. Ideally, the common alloying elements in alloy steel include the following;

  • Silicon
  • Copper
  • Lead
  • Tungsten
  • Boron
  • Cobalt
  • Manganese
  • Molybednum

On the other hand, the notable alloying elements in stainless steel are as follows;

  • Chromium (10.5%) – It gives the material its general corrosion resistance.
  • Nickel
  • Carbon
  • Cobalt
  • Aluminum
  • Copper
  • Niobium
  • Tungsten
  • Vanadium

Fabricating Alloy Steel Vs. Stainless Steel

Ordinarily, the fabrication processes for alloy steel and stainless steel are relatively similar, and they include the following;

  • Machining
  • Work hardening
  • Brazing (Silver soldering)
  • Welding
  • Cold drawing
  • Cutting (Plasma cutting, waterjet cutting, abrasive disc cutting, slitting, laser cutting, bandsawing)
  • Bending

All these fabrication techniques use different tools and procedures to attain the desired results.

Fabricating Alloy Steel Vs. Stainless Steel
Life Span Of Alloy Steel Vs. Stainless Steel

Life Span Of Alloy Steel Vs. Stainless Steel

Alloy steel and stainless steel are both durable materials since they are formed from a wide range of alloying elements.

Both exhibit high corrosion resistance, high strength to weight ratio, excellent strength, and great performance under harsh conditions.

The actual service lifespan of the alloy steel and stainless steel, however, is dependent on numerous factors, including the precise application.

For instance, alloy steel like D2 used in several industrial shear blades is quite durable material for tooling.

Thus, depending on the application and alloy composition, these materials can last for several years.

Corrosion Resistance: Alloy Steel Vs. Stainless Steel

Stainless steel has a better corrosion resistance than alloy steel. Essentially, stainless steel has a larger chromium composition percentage of about 10.5% to 12%.

On the other hand, alloy steel contains a smaller percentage of chromium percentage. It is this alloying element that enhances the corrosion resistance ability of a particular metal.

Thus, stainless steel can withstand applications with harsh corrosion elements better than alloy steel.

Corrosion Resistance_ Alloy Steel Vs. Stainless Steel
Welding Alloy Steel Vs. Welding Stainless Steel

Welding Alloy Steel Vs. Welding Stainless Steel

The weldability of alloy steel is dependent on the specific material compositions.

Generally, low alloy steels tend to be more weldable than high alloy steels but often require knowledge of joint configuration, service, and material subgroup type.

Besides, welding alloy requires ideal preparation because quenched and tempered alloy steels tend to be susceptible to cracking if precautions are overlooked.

On the other hand, effective stainless steel welding requires use of a resistance weld for an easy and smoother process.

Hence, it is easier to weld stainless steel than alloy steel since the former exhibits high resistance to current flow.

Therefore, it is easier and quicker to generate weld joints on stainless steel compared to alloy steel.

Aesthetics: Stainless Steel Vs. Alloy Steel.

Stainless steel portrays a monolithic, clean, modern aesthetics with a silver-white lustrous or shiny appearance.

Moreover, the coating of stainless steel with chromium makes it more attractive in its natural state without need for painting.

Alloy steel has a matter gray or mottled appearance, thus not necessarily as shiny as stainless steel.

However, the metallic luster appearance of alloy steel still gives it ideal aesthetics but not necessarily to the extent of stainless steel.

Aesthetics_ Stainless Steel Vs. Alloy Steel.
Strength Of Alloy Steel Vs Stainless Steel

Strength Of Alloy Steel Vs Stainless Steel

Generally, the tensile strength of alloy steel often ranges from 758 – 1882 Mpa. Stainless steel, on the other hand, exhibits a tensile strength range of 515-827 Mpa.

Thus, it means alloy steel are better suited for a wide range of applications where strength is a significant concern.

Brittleness Of Alloy Steel Vs Stainless Steel

Alloy steel is not brittle since atoms in its crystals are more or less arranged regularly. However, it becomes a bit ductile when switched from one structure to another.

On the other hand, stainless steel is more brittle than alloy steel since it contains a higher amount of nickel composition than the latter.

Even so, most stainless steel materials tend to become more brittle; thus ideal to know the specific brittle grades of stainless steel.

Brittleness Of Alloy Steel Vs Stainless Steel
Malleability Of Alloy Steel Vs Stainless Steel

Malleability Of Alloy Steel Vs Stainless Steel

Stainless steel is more malleable than alloy steel since it consists of higher nickel composition than the latter. Technically, nickel improves vital properties such as ductility.

Alloys steel, on the other hand, has a disrupted ions arrangement making it harder for layers to slide over each other. Hence, it is less malleable than pure metal.

Magnetic Properties Of Stainless Steel Vs Alloy Steel

Ordinarily, both alloy steel and stainless steel have a chemical composition that contains iron.

But alloy steel is categorized as a ferromagnetic material, implying that it is strongly attracted to magnets.

Stainless steel, on the other hand, has varieties of iron; thus, the actual grade determines whether it is magnetic or non-magnetic.

For instance, austenitic stainless steel is non-magnetic, whereas ferritic stainless steel is highly magnetic.

Magnetic Properties Of Stainless Steel Vs Alloy Steel
Resistance To Temperature_ Stainless Steel Vs Alloy Steel

Resistance To Temperature: Stainless Steel Vs Alloy Steel

You can use stainless steel in high temperatures of between 500-1150°C.

It shows this material has better resistance to temperature, thus suitable in an application where prolonged heating is a concern.

Alloy steel also has better heat resistance, depending on the specific alloy composition.

For instance, cobalt chrome nickel-based alloys, nickel-based alloys, and molybdenum titanium alloys steel offer better temperature resistance.

Types Or Grades Of Stainless Steel

Types Or Grades Of Stainless Steel
Types Or Grades Of Stainless Steel

Stainless steel is graded into three categories based on crystalline structure of its irons, which include austenitic, ferritic, and martensitic. Composition of austenitic stainless steel is at least 10.5% and 8-12% nickel, nitrogen, carbon, and other elements in solution. The categories are further subdivided into series and grades reflecting the specific alloy’s durability, heat resistance, and quality.

Stainless steel types under austenitic grade include; Type 301, Type 302, Type 303, Type 304, Type 309, Type 316 and Type 321.

Ferritic stainless steel consists of straight chromium non-hardenable stainless alloys with chromium composition of 10.5% to 30%.

Martensitic stainless steel grade can be hardened and also tempered through several techniques of aging and heat treatment.

Stainless steel types under ferritic and martensitic grades include; Type 408, Type 409, Type 410, Type 416, Type 420, Type 430, Type 440.

Figures listed after the grade refer to chemical composition of the item, more particularly to its chromium and nickel percentages.

Types Of Grades Of Alloy Steel

Types Of Grades Of Alloy Steel
Types Of Grades Of Alloy Steel

Alloy steel are available in different sub-categories, which include the following;

  • Low-alloy steel
  • High-strength low alloy steel
  • Micro-alloyed steel
  • Tool steel
  • High alloy steel
  • Micro-alloyed steel
  • Maraging steel
  • Advanced high-strength steel

Typically, low alloy steels contain less than 8 wt.% non-iron elements. High alloy steels, on the other hand, consist of more than 8 wt.% non-iron elements. However, both exhibit superior mechanical properties compared to carbon steel.

Chemical Composition On Alloy Steel Vs Stainless Steel

Chemical Composition On Alloy Steel Vs Stainless Steel
Chemical Composition On Alloy Steel Vs Stainless Steel

Alloy steel is made of various elements with varying chemical compositions to enhance different properties of the material. Here are the main chemical composition of alloy steel;

  • Aluminum – 0.95–1.30 wt.%
  • Copper – 0.1-0.4 wt.%
  • Silicon – 0.2-2 wt.%
  • Vanadium – 0.15 wt.%
  • Sulfur – 0.08 – 0.15 wt.%
  • Chromium – 0.5 – 18 wt.%
  • Nickel – 2-20 wt.%
  • Manganese – 0.25-0.4 wt.%
  • Molybdenum – 0.2 – 0.5 %

The general enhanced properties of stainless steel are a result of chemical composition of its different alloying elements as follows;

  • Carbon – 0.08 wt.%
  • Manganese – 2.00 wt.%
  • Sulfur – 0.05 wt.%
  • Phosphorous – 0.045 wt.%
  • Silicon – 0.75 wt.%
  • Chromium – 16-18 wt.%
  • Nickel – 10-14 wt.%
  • Nitrogen – 0.1 wt.%
  • Molybdenum – 2.0 – 3.0 wt.%

Advantages Of Stainless Steel Vs Advantages Of Alloy Steel_
Advantages Of Stainless Steel Vs Advantages Of Alloy Steel?

Advantages Of Stainless Steel

  • Excellent corrosion resistance thus can withstand any corrosive surrounding it is exposed to.
  • High impact resistance and strength hence guarantee strong structures.
  • Great aesthetic appearance making it ideal for a wide range of decorative applications.
  • Guarantees long-term service hence giving value for money.
  • Highly sustainable since it is fully recyclable.
  • Hygienic and easy to clean.
  • Incredible fire and heat resistance

Advantages Of Alloy Steel

  • Exceptional corrosion resistance hence suitable for applications where corrosion is a concern.
  • Produce durable products, which give value for investment.
  • High thermal and electrical conductivity
  • Excellent tensile strength guarantees strong parts and components in different applications.
  • It exhibits less distortion and cracking, thus easy to fabricate
Disadvantages Of Stainless Steel Vs. Disadvantage Of Alloy Steel
Disadvantages Of Stainless Steel Vs. Disadvantage Of Alloy Steel

Disadvantages of stainless steel

  • Relatively low machinability and weldability limit its use in different applications.
  • Comparatively expensive, thus costly for large-scale applications
  • Tends to get dirty quite fast therefore needs frequent cleaning
  • It gets scratched easily

Disadvantages of alloy steel

  • Lower formability, machinability, and weldability
  • Usually expensive depending on the level of added iron
  • Tend to be brittle at high-stress levels

People Also Ask:

Is Alloy Steel Better Than Stainless Steel?

It depends on the specific alloy steel, but they both have varied characteristics making them ideal for different applications.

Do You Consider Stainless Steel An Alloy Steel?

Yes.

Stainless steel is alloyed using iron, chromium, nickel, and other metals.

Is Alloy Steel Rust Resistant?

Yes.

However, the alloy must be made using ferrous metals.

What Are The Applications Of Alloy Steel?
  • Military vehicles
  • Chemical processing
  • Construction equipment
  • Pressure vessels
  • Oil drilling
  • Structural components
  • Automotive industry
Where Do Use Alloy Steel?
  • Structural sections
  • Rails
  • Rods
  • Bars
  • Flanges
  • Decoration strips
  • Signage

More Resources:

Steel Sheet Metal Fabrication

Stainless Steel Fabrication

Mild Steel Fabrication

What Is Alloy Steel

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