In this article, we will talk about the differences between Carbon Steel and Stainless Steel in terms of the manufacturing process, the properties and the applications.
It is stated that over 1.5 billon tons of steel are produced every year to make products as diverse as sewing needles and structural beams for skyscrapers.
Carbon Steel is a type of steel where the main alloying element is carbon, and the properties depend on the percentage of carbon present. It is comprised of iron and carbon while carbon is the most common category of steel. Carbon steel can also contain small amounts of manganese, silicon, and copper.
While, Stainless Steel contains iron, carbon and at least 10.5% chromium content. The chromium is the key — it reacts with oxygen to create a passive layer that protects the steel from corrosion.
Properties of Carbon Steel
Carbon Steel is characterized by a high carbon content, usually up to 2.1% of its weight. The American Iron and Steel Institure (AISI) further defines carbon steel by meeting the following criteria:
- No minimum content requirement for chromium, cobalt, nickel, titanium, tungsten, vanadium or other corrosion-resistant metals.
- Minimum required copper content must not exceed 0.40%
- Maximum content of manganese must not exceed 1.65%
- Maximum content of copper must not exceed 0.6%
- Maximum content of silicon must not exceed 0.6%
Carbon Steel is mainly used for swords, knives and other bladed weapons due to the high-carbon content. In Japan, swordsmiths pioneered a special type of high-carbon steel, tamahagane, for use in weapons like the katana.
However, carbon steel lacks the corrosion-resistant properties of its stainless steel counterpart.
Although it’s stronger and more durable than stainless steel, carbon steel may rust and corrode when exposed to moisture. Even small amounts of moisture can cause carbon steel to rust.
Furthermore, carbon steel is less ductile than stainless steel.
Properties of Stainless Steel
Normally, when iron-based metals like steels are exposed to oxygen, they undergo a chemical transformation, known as oxidation, that changes their properties. The iron oxidizes while subsequently turning the otherwise hard iron into a reddish-brown metal (iron oxide). Eventually, the iron oxide will oxidize to the point where it disintegrates completely.
Stainless Steel is designed to protect against oxidization. It features a minimum Chromium content of 10.5% by mass.
This is important because Chromium, unlike iron, isn’t susceptible to oxidation. Chromium can be exposed to oxygen without developing rust or corrosion, making it an invaluable element in the creation of stainless steel.
Stainless Steel features a protective layer of Chromium that creates a barrier between environmental oxygen and the metal’s iron content.
Austenitic stainless steels are the most common type of stainless steel. SUS303 and SUS304 are the most common types of austenitic stainless steels, and SUS316L is a variant because they’re weatherproof, they work just about anywhere. Due to their higher costs, metal 3D printing can be a viable fabrication method for these parts.
Another type is Martensitic Stainless Steels, offer better mechanical properties to austenitic steels at the cost of ductility. Example of martensitic stainless steel are 17-4PH, it can be heat treated to fit a variety of material properties.
For more information about stainless steel products, you may visit E Steel Sdn Bhd.
Should I pick Carbon Steel or Stainless Steel ?
Carbon Steel and Stainless Steel are different, but one is not necessarily superior to the other. Each material has advantages and disadvantages, the key is to match the steel to the job requirements.
|High Carbon Steel||Stainless Steel|
|Vulnerable to rust||Resistant to rust|
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