by Composition and Properties
Carbon steel is one of the most widely used types of steel because of its versatility. It is created by combining iron with carbon in concentrations between 0.02% and 2.1% by weight. This small addition of carbon is what distinguishes it from pure iron. It significantly increases the hardness and strength of the base iron material while maintaining its ductility and weldability. The carbon bonds with the iron to form iron carbide, which improves the crystal structure of the metal making it more resistant to stress and strain.
Some key Carbon Steel properties that result from the iron-carbon alloy include high strength and hardness up to a point, though carbon steel lacks toughness and is susceptible to corrosion. Its yield strength typically ranges between 200-600 MPa depending on carbon content, with higher carbon resulting in higher strength up to around 0.3% after which toughness starts to reduce significantly. Other factors like alloying additions, heat treatment processes and grain size also influence the achieved mechanical properties.
Forming and Machining Capabilities
Due to its moderate strength and ductility, they possesses good formability as well as workability. It can be easily hot or cold formed into various sheet metal and structural profiles through techniques like rolling, forging, pressing, etc. With appropriate lubrication and tool design, they may also be readily machined to tight tolerances using conventional chip removal methods like turning, milling, drilling, etc. It machines cleanly without any built-up edge or work hardening issues. This versatility in forming and machining gives them an advantage over other metal alloys in cost-effective fabrication across diverse industries.
Major Industrial Applications and Uses
With such a balance of mechanical properties, cost and fabricability, they finds extensive use in construction, machinery, automotive, tools and equipment manufacturing. Some examples include:
– Construction industry: Carbon steel rebar and structural I-beams provide the tensile strength in reinforced concrete buildings and bridges. Steel pipes and tubing are common in plumbing, drainage and irrigation systems as well.
– Machinery: General purpose machine parts, equipment housings, industrial vehicles and agricultural implements employ them based on its durability and availability.
– Automotive: The chassis, body panels and powertrain components of commercial vehicles and some passenger cars are made from various steel grades.
– Tools: Blades, cutting edges, handles and hardware of hand tools, kitchen knives, garden tools rely on the combination of hardness and toughness achieved in them like tool steels.
– Shipping: Carbon steel plates are the primary material for hull construction in marine vessels from bulk carriers to container ships due to its cost-effectiveness.
Surface Treatments and Coatings
While useful as a work hardening metal, it suffers in corrosive environments due to its propensity to rust if not properly protected. Various surface treatments are commonly applied that impart corrosion resistance without majorly altering the steel properties. Hot dip galvanizing involves dipping the fabricated part in a bath of molten zinc coating, resulting in a thick protective zinc layer that slows down oxidation. Another widespread option is to paint over exposed its surfaces, with primers and finishes specifically formulated to boost adhesion and longevity outdoors. Metallic coatings like aluminum-zinc, tin-zinc and aluminum also effectively passivate steel. For safety-critical internal automotive components, hard chromium plating delivers a durable, corrosion-proof and low-friction alternative to conventional paints or oils. Proper pre-treatment, application technique and process control ensures the protective film withstands the intended service conditions.
Alloying Additions and Variants
While carbon remains the primary alloying element in typical steels, low level additions of alloying metals like manganese, silicon, chromium, nickel, molybdenum may be included to fine tune specific material properties as needed. Examples include:
– Manganese steel contains 1-2% Mn and has an extremely high hardness and abrasion resistance making it suitable for applications like bulldozer blades, hoppers, crusher jaws etc.
– Stainless steel involves chromium content greater than 11% to develop a passive chromium oxide layer blocking rust and corrosion even without coatings. This comes at the cost of higher material and manufacturing costs than regular carbon steel.
– Alloy steels contain precisely controlled quantities of various elements like nickel, chromium, molybdenum and vanadium to improve characteristics like tensile strength, toughness, hardenability beyond plain carbon steels. Gear steels, spring steels fall under this category expanding application range.
given its excellent cost-performance, forming capabilities and broad spectrum of commonly available grades, carbon steel remains the workhorse metal material found in general engineering industry. Future alloy innovations may further augment its advantages.
*Note:
1. Source: Coherent Market Insights, Public Source, Desk Research
2. We have leveraged AI tools to mine information and compile it.
