The world of steel is very confusing. There are various types of steel, grades, and compositions available in the market. It requires keen attention to the details of the variety. Here we will discuss – Chrome Steel vs Stainless Steel. Both are very similar to each other appearance-wise, primarily used in households. The main difference between them is in their makeup. Let us explore the difference between chrome steel and stainless steel.
What is Chrome Steel?
Chrome steel also known as bearing steel is a coating of chromium applied to the surface of another raw metal via electroplating. It belongs to a non-alloy family which is brittle in its natural state. Whereas it acts as an essential mineral used for improving steel composition. The shiny effect is the result of the chromium plating which protects from corrosion and rust on the steel. Chrome steel has many applications such as kitchen utensils & appliances, faucets, doorknobs, musical instruments, automotive components, and agricultural equipment. Chrome plating is cost-effective as compared to stainless steel.
What is Stainless Steel?
Stainless steel is a mixture alloy of iron and carbon, composing a minimum of 10.5% chromium, less than 1.2% carbon, nickel, manganese, copper, silicon, and aluminum. Stainless steel is corrosion resistant, scratch & tarnish resistant, has magnetic properties, as well as highly durable. It is generally processed in sheets, bars, and tubes. Which offers a range of utilities such as – kitchen cutlery, food processing, decorative items, HVAC, railroad, and marine components. It is mainly used in sectors facing potential moisture or high levels of usage.
Types of Stainless Steel
Stainless steel is categorized into different types on the basis of the ratio of various metals present in the alloy. Each type has different grades only stainless steel manufacturers will help us to understand the properties of the alloy like toughness, magnetism, corrosion resistance, and alloy composition. The four distinct types of stainless steel are as follows:
Martensitic Stainless Steel
Martensitic Grade is straightforward chromium steel without nickel made to be corrosion resistant and hardenable. These grades are magnetic in nature and used where hardness, strength, and wear resistance are required such as fabrication of medical instruments mechanical valves, and turbine parts. The various grades of martensitic stainless steel are described below:
Type 410 is a fundamental martensitic grade type made of low-content alloy. It is cheap and heat-treatable general-purpose stainless steel. It is generally used where high corrosion resistance is not mandatory and minimal strength is needed, such as fasteners.
Type 410S has a comparatively low content of carbon available in it but offers good weldability with lower hardenability. It is a non-heat treatable version of 410 with 12% chromium content used for general purposes. The cold working method is used for 410S stainless steel.
Type 414 is functionally a type 410 stainless steel with the inclusion of nickel metal in it. The addition of nickel makes it harder than 410 with similar strength levels and has fairly good machinability. This type is applicable in mining equipment such as valves, seats, forged shafts, and spindles.
Type 416 is a martensitic, chromium steel alloy with free machinability properties. The addition of sulfur makes it comparatively less corrosion-resistive, has poor weldability, and has poor formability This type can be seen in parts of washing machines, gears, nuts, bolts, shafts, and valves.
Type 420 is a modified version of type 410 stainless steel with good corrosion resistance, high toughness, strength, and low weldability. In fully hardened conditions maximum corrosion resistance is attained. Needle valves, knife blades, surgical instruments, and shear blades are some of the applications of this type.
Type 431 is a martensitic, heat-treatable stainless steel grade with the best corrosion resistance, high torque strength, high toughness, and tensile properties. However, it has poor weldability properties due to toughness. Some applications of this type are laboratory equipment, marine systems, pumps, and shafts.
Type 440 also known as Razor Blade Steel, has a high content of carbon in it. It gains the highest hardness, wear resistance, and strength more than all stainless steel grades on heat treatments. It provides the best corrosion resistance to food, alkalis, mild acid, and freshwater. Applications – Chisels, surgical equipment, high-quality knife blades, etc.
Ferritic Stainless Steel
Ferritic stainless steel has a high chromium content of nearly 10% – 30% and a carbon content of less than 0.20% alloy. It is non-hardenable, magnetic, good corrosion resistive, and oxidation resistive, high hardness, and extraordinarily shiny when polished. This stainless steel is popular in indoor appliances as well as in decorative items. Different grade types of ferritic stainless steel are discussed as follows:
Type 430 is a ferritic stainless steel with mild corrosion resistance that can be easily bent, drawn, or stretched. It is corrosion-resistant to nitric acid, sulfur gases, and organic food acids. So, it is applicable to a variety of interior and exterior cosmetic items. Due to its relatively high carbon content, it has poor weldability.
Type 405 is a ferritic stainless steel having 12% chromium content with good corrosion resistance, weldability, and machinability. It is non-vulnerable to hardening when cooled to high temperatures. This grade type is used in steam nozzles, partitions, annealing boxes, and quenching racks.
Type 409 is a heat-resistant ferritic stainless steel offering good corrosion and oxidation resistance in comparison to carbon steel. It has good weldability and formability properties and is not used in decorative items. Applications of this grade are catalytic converter stem, mufflers, and exhaust systems.
Type 434 is a widely used non-hardenable ferritic stainless steel having good corrosion resistance when molybdenum is added to it. Blanking, shearing, and deep drawing operations can be performed on it due to its high ductility. It does not react to heat treatment. It is used in automotive trim applications and other exterior environments.
Type 436 is a variation of type 434 with the inclusion of columbium and molybdenum for good corrosion resistance and heat resistance. It looks similar to a Chromium plate when polished. It has comparatively good weldability and is magnetic in both conditions – cold rolled tempers and annealed. Appliance trims and automotive parts are the applications of this grade.
Type 442 is ferritic stainless steel with improved corrosion scaling due to the addition of chromium content. It is one of the widely used precipitation hardening grades in various industries. It has good corrosion resistance, high hardness, toughness, and strength. Some applications are furnace and heater parts.
Type 446 is a non-hardenable, ferritic stainless steel with excellent mechanical properties. At high temperatures, it is highly corrosion-resistant and oxidation-resistant. However, its ductility is low due to extra chromium content. Some applications of this grade are x-ray tube bases, boiler baffles, oil burner components, and glass molds.
Austenitic Stainless Steel
The word austenite means face-centered cubic structure formation when the iron is heated at a high temperature. Stainless steel naturally becomes austenitic when nitrogen and nickel are added to it. It is non-hardenable, non-magnetic with good formability and excellent corrosion resistance properties. The various forms of austenitic stainless steel are described below:
L-grade stainless steel is a low-carbon grade that is used to provide corrosion resistance after welding. To avoid carbide precipitation, carbon content is kept within the range of 0.03%. Carbide precipitation happens when the temperature range is 450 to 850 degrees Celsius. L-grade steels are available in the form of bars, plates, and pipes.
H-grade stainless steel is a relatively high carbon grade where carbon content ranges from 0.04% to 0.10%. At high temperatures, this steel has high strength and corrosion resistance. It is used in the form of plates and pipes. The most common form of H grades used is Type 304, Type 316, and Type 317.
Duplex Stainless Steel
Duplex Stainless Steel is a combination of the properties of austenitic and ferritic steel. It exhibits greater toughness and higher weldability than ferritic steel and has higher corrosion resistance and better strength than austenitic steel. Advanced engineering has increased the number of applications mainly in corrosion-resistive environments such as sour gas pipelines and chemical reaction vessels. The different grade types of this stainless steel are as follows:
Type 2205 is duplex stainless steel used in high-pressure and high-corrosion environments. It contains 22% Chromium, 3% Molybdenum, and 5-6% nickel nitrogen. Which cannot be thermally hardened and has poor machinability due to its high hardness. It is typically used in transport, storage, and chemical processing, high chloride and marine environments, paper machines, and liquor tanks.
Type 2304 is duplex stainless steel with 23% chromium and 4% nickel present in it. It is highly resistant to stress corrosion cracking, has high hardness and strength, high thermal conductivity, low thermal expansion, and easy fabrication. It is used in storage tanks, bridges, water heaters, heat exchangers, and pressure vessels.
Precipitation Hardening Stainless Steel
Precipitation Hardening is a heat treatment process to increase the yield strength of stainless steel. It is a three-step process – firstly, treat the metal with a solution at a high temperature then rapid cooling takes place till it is in the form of a supersaturated solid, and at last heat is provided to the supersaturated solution at an intermediate temperature. This process induces precipitation. It has fair to good corrosion resistance. The most known grade types of this steel are discussed as follows:
Type 17-4 grade is a mixture of chromium-copper maternistic PH stainless steel. It possesses high strength, hardness, good corrosion resistance, good fatigue and formability properties, and minimal distortion upon heat treatments. This type is mainly used in a variety of springs and showers, heat exchangers, power boilers, and components used in high strength.
Type 15-5 is the modified version of the chromium-copper-nickel Type 17-4 martensitic precipitation hardening stainless steel. It has a more refined structure which leads to the high toughness of the material. The material is cold-worked to improve its yield strength. Some applications of this grade type are marine gas turbine compressor sections, hollow shafts, engine parts, aircraft components, and nuclear reactor components.
Types of Chrome Steel
The process of electroplating a thin layer of the chemical element chromium onto the metal to protect it from wear and corrosion is known as a coating. This widely utilized technique uses a chromium compound to coat various metal surfaces and is employed for a variety of artistic and industrial purposes. These include molds, screws, shafts, rotors, textile and printing tools, shafts and rotors, shafts and pistons, hydraulic cylinders and pistons, automotive and mechanical components, press punches and tooling, mining and agricultural equipment, shafts and rotors.
These four distinct chromium uses are:
Hard Chrome Coating
An electrolytic process called hard chrome plating puts chromium on a sublayer. All natural engineering alloys may use it, and it offers excellent substrate bonding. Hard chrome is the greatest material to use for metal and metal sliding because it increases sturdiness, wear resistance, and hardness while producing a low element of resistance. Due to its thickness, hard chromium plating is frequently used on exterior surfaces to facilitate additional cutting and to produce greater pore size.
Crack-free Chromium Coating
Hard chrome is an improved form of corrosion-resistant chrome that may be used on irregular and non-uniform-shaped objects. Stainless steel, copper, and brass are just a few of the many metals that may use crack-free chromium coating even at low temperatures. Although any chromium coating may be applied to both soft and hard surfaces, this method is better suited for tougher surfaces with virtually no risk of delamination or flaking.
Thin Dense Coating
Internal spaces and inner diameters are often coated with a thin, dense coating, which improves consistency and reduces the need for honing plated surfaces. The use of chromium in thin, dense coatings results in coatings with smoother surfaces, longer fatigue lives, and greater rust resistance. Despite being a thin coating, it frequently costs more than hard chrome because of its chromate conversion. When used on dies, airplanes, and medical equipment, thin dense coatings provide a number of advantages, such as longer wear life, better heat resistance, and stronger corrosion protection.
Although decorative coating serves fewer purposes than hard chrome plating, it is still important in many different sectors. When applied to vehicle components, tools, cooking utensils, and musical instrument hardware, it still offers a thin protective covering while having less strength and durability. Additionally, decorative chrome plating protects metals against rust and wear, especially when they are in corrosive or moist environments. It offers a clean, bright, and smooth look, making it the perfect choice for many consumer items. Because decorative chrome plating is much smaller than hard chrome plating, which is more robust, it is quite useful.
In conclusion, when deciding between stainless steel and chrome steel, your choice will ultimately depend on your preferences and specific requirements. Chrome steel is an excellent option if aesthetics and visual appeal are important to you. The shiny luster of chrome steel creates a favorable impression and can enhance the overall appearance of an item or product. On the other hand, stainless steel is known for its durability and longevity. It is a robust metal that can withstand corrosion, making it suitable for a wide range of applications. While stainless steel may not have the same level of visual attractiveness as chrome steel, it offers the advantage of being able to apply unique finishes that can still meet your aesthetic needs to some extent. Ultimately, both stainless steel and chrome steel have their own advantages and disadvantages.