Steel has one popular variant- stainless steel which is also known as SS. The two crucial industrial commodities are extensively used in a wide variety of sectors ranging from building, construction, etc. Both are alloys made up of metals and various other elements such as nickel, manganese, molybdenum, titanium, cobalt, boron, vanadium etc. Price is one major point of differentiation between them. Stainless steel price is slightly higher than steel prices due to its corrosion-resisting properties.
In this article, let’s explore the difference between them.
Properties
Mentioned below are the details:
- Steel: The most produced steel in the world, carbon steel, is made using carbon and iron. It comes in three subcategories:
- Low Carbon: It contains approximately 0.03%-0.15% carbon.
- Medium Carbon: It contains approximately 0.25%-0.50% carbon.
- High Carbon: It contains approximately 0.55%-1.10% carbon.
As the amount of carbon increases, the steel becomes harder and more difficult to bend and weld.
The elements are mixed together to make steel add different properties to it. The key properties are mentioned below:
- Toughness: It promotes resistance to fracture when exposed to pressure or stress.
- Hardness: It enables it to withstand abrasion and friction.
- Ductility: When force is applied, it enables the metal to change shape without cracking.
- Yield Strength: It is the maximum stress level a material can absorb before bending or warping.
- Tensile strength: It is the capacity of a material to withstand tensile stresses.
- Stainless Steel: It is an alloy of iron and chromium containing a minimum of 10.5% chromium. The precise components and their ratios vary as per the grade. The high chromium proportion forms an invisible layer on steel’s surface, thus, preventing it from forming corrosion stains.
Common additives in stainless steel include nickel, carbon, manganese, copper, silicon, molybdenum, and sulfur. Being an alloy of iron, its properties are similar to steel. Additionally, it offers corrosion resistance all thanks to 10.5% chromium and stands true to its name. Stainless steel pipe is one of the most popular products in this category.
Steel Vs. Stainless Steel
Let’s have a look at the major points of difference between steel and SS:
- Composition: The former comprises carbon, iron, as well as other metals. The latter comprises chromium, iron, as well as other metals.
- Tensile Strength: The former has high tensile strength while the latter has relatively lower tensile strength that offers ease of fabrication.
- Corrosion And Rust: The former is bound to corrode and rust while the latter has amazing corrosion and rust resistance properties.
- Heat Resistance: The former does not resist heat while the latter has excellent heat resistance properties.
- Applications: The former is typically used for the construction of automotive applications, chemical processing machines, ships, pipelines, etc. On the other hand, the latter is used for manufacturing medical instruments, food processing machines, and kitchen appliances.
- Price: The stainless steel price is costlier than steel pipe because of the presence of different alloying elements and the additional benefit of a safety net against corrosion.
What Causes Corrosion?
A natural process, corrosion occurs as metals react to their environment, which leads to metal properties’ deterioration. Different factors are mentioned below that cause corrosion:
- Moisture: Moisture or water is a key factor responsible for various corrosion processes. Water’s presence enables electrolyte formation, allowing not just ions’ flow, but facilitating electrochemical reactions on the surface of metal.
- Chemical Reactions: Often corrosion is a result of chemical reactions between substances and metals. Electrochemical corrosion is a highly common type of corrosion, which involves the flow of electric current between anodic and cathodic areas on the metal surface.
- Oxygen: The presence of oxygen, especially in moisture, contributes a great deal to corrosion as the between metal and oxygen leads to the formation of metal oxides, that compromise the metal’s integrity.
- Salt: Salt, chloride ions to be specific speed up the corrosion process. It increases electrolyte conductivity and promotes rapid electrochemical reactions. In marine environments, with common saltwater exposure, it is a rampant occurrence.
- Pollutants: Some industrial pollutants, sulfur compounds to be specific, contribute to corrosion by reacting with metal surfaces and forming sulfides.
- Acids And Bases: Exposure to alkaline or acidic environments accelerates corrosion as acids tend to react with metals. This, in turn, not only forms salts but releases hydrogen gas. Bases, on the other hand, can form oxides upon reacting with metals.
- Microbes: Microorganisms such as fungi, algae, and bacteria cause corrosion by producing corrosive byproducts or creating conditions that trigger the corrosion process.
- Mechanical Stress: Metal surfaces upon experiencing mechanical stress can create corrosion-friendly sites. When stress and a corrosive environment amalgamate, stress corrosion cracking occurs.
- Galvanic: In case two different metal types come in electrical contact and get electrolyte exposure, galvanic corrosion is likely to occur.
- Temperature: Increased temperatures can ramp up corrosion speed by enhancing the chemical reactions kinetics and promoting the metal ions diffusion.
Which One is Better?
Steel and SS are both reliable metals which are used widely. In case you are wondering which one is better, the answer boils down to the usage and the environmental conditions. Whichever type of steel fulfils your purpose of use is the better option for you. When it comes to zeroing down on a better option, one size doesn’t fit all. Simply put, what is better for you might not be better for me.
Over to You
Both steel and SS offer different properties at different prices. Both are tough, strong, and dependable alloys that have a myriad of uses. Both steel types are capable of lasting long in outdoor environments. With that being said, SS is best suited when it comes to long-term usage that too in abrasive conditions.