Introduction
Chrome vs stainless steel – what is the difference? At first glance, chrome steel and stainless steel products appear identical. Their shiny, smooth, and durable exteriors are popular with household appliances and decorative items.
Kingsun Product Page
Chrome is a chemical coating process where a thin chromium layer is applied to a raw metal substrate. Chromium is an element classified as non-stainless steel that is brittle in its natural state but is a critical additive in steel composition for a high strength part. It is not considered an alloy.
Stainless steel is a family of iron alloys typically processed into sheet metal and bar or tube stock that contains at least 10.5% chromium and may include carbon, nickel, nitrogen, aluminum, silicon, copper and manganese.
Characteristics
Chrome
Chrome is also known as chromium or chromium plating. As previously mentioned, this layer of chromium is applied onto the surface of a plastic or metal object through electroplating, for industrial purposes and decorative applications.
Stainless steel and chrome steel share similar aesthetic qualities, including a shiny appearance. Chrome, however, offers a more lustrous and polished look than stainless steel.
Chrome steel features a low coefficient of friction and protects against corrosion. Stainless steel has a smooth, non-absorbent surface that is very resistant, non-toxic and can be thoroughly cleaned with aggressive disinfectants and may be sterilized. Chrome plating does not tolerate aggressive cleaning agents.
Stainless steel
Side by side, you’ll note that stainless steel is typically polished to a high, mirror like finish that is duller and darker than what you see with chrome plated products.
While chrome steel is hard and dense, stainless steel stands alone as one of the hardest and strongest metals next to carbon steel.
Stainless steel is more durable than chrome, offering corrosion resistance as well as scratch and tarnish resistance. However, this is somewhat dependent on the environment, as this metal is not completely immune to all stains or even wear and tear.
Stainless steel alloy: Families & grades
There are four varieties of stainless steel families:
- Austenitic – The most widely used stainless steel
- Ferritic – The most cost-effective family of stainless steel products
- Duplex – The most recent stainless steel alloys developed
- Martensitic & Precipitation Hardening – Used for hardened edge applications. Magnetic after hardening.
The grade of the alloy is another factor. 200 series of stainless steel grades are known for high work hardening. 300 series stainless steel can withstand extremely high temperatures. 400 series stainless steel provides greater strength and durability.
Decorative and Hard Chrome Plating
Plating thickness dictates the difference between decorative plating and hard chrome plating. The plating for the less expensive decorative items is thin (5-8 microns) and is often called nickel-chrome plating since it is applied over an initial layer of nickel plating.
Hard plating (10 to 500 microns) has a low friction coefficient that acts as a lubricant. Time in the electroplating bath dictates the thickness.
Uses
Chrome
Chrome steel has many different applications including:
- Kitchen utensils and appliances
- Doorknobs, faucets and fixtures
- Tools
- Musical instruments
- Automotive components
- Dies, molds, and tooling
- Mining and agriculture equipment
Stainless Steel
Applications for stainless steel include:
- Cookware, kitchen cutlery, and food processing
- Surgical tools and medical equipment
- Appliances
- Decorative items
- Hardware items
- HVAC
- Architecture
- Storage tanks and pipes
- Automotive, railroad and marine components
Manufacturing processes
Stainless steel begins as an iron alloy composed of chromium, carbon, nitrogen, manganese, silicon, molybdenum, and nickel. These elements are tailored for different purposes.
Materials melted for 10-12 hours.
- Materials melted for 10-12 hours
- Excess carbon removed. Metal desulfurized
- Adjust chemical composition
- Pour into casts
- Hot and cold roll operations & annealing
- Cut to size
- Finishing operations
Chrome plating is a process of applying a thin layer of chromium onto a substrate (metal or metal alloy) via electroplating.
If you are looking for more details, kindly visit High-Purity Metal Chromium for Sale.
- Material cleaned, manually cleaned
- Chemically treatment
- Electrolytic chromium bath
Advantages & disadvantages
Recent improvements in plating and steel production lessen the differences. The remaining advantages are as follows:
Chrome plating
- Low friction
- Reduced weight
- Lesser expense
Stainless steel
- Magnetic properties
- Weldability
- Hardness
- Durable
These processes are constantly improving, so the differences between chrome steel and stainless steel may eventually vanish.
Is stainless steel or chrome better?
The answer to this question depends entirely on your needs and circumstances. If you require the best look or appearance at low cost, chrome steel is the better option, as it is usually less expensive and offers a shinier luster than stainless steel.
However, this comes with trade-offs, since stainless steel is stronger and is more durable. Long-term exposure to water, heat elements and contact with hot and cold air will cause chrome plating to corrode. If the main objective for your project, stainless should be your metal of choice.
Metal Supermarkets stocks a wide variety of chrome plated and stainless steel products in many different shapes and grades. If you have further questions, reach out to your closest store for assistance with metal sourcing.
Corrotherm supplies and distributes a wide range of nickel alloys, intended for all manner of end uses and applications within the oil and gas industry. But why are these nickel-based alloys used in such aggressive environments rather than pure metals?
The famous Aristotle quote, ‘The whole is greater than the sum of its parts,’ is particularly apt here. Alloys are a mixture of a number of different metals and other elements, each lending their own properties to the compound. Alloys can, therefore, take on these properties within the mixture, blending together the best of all the metals and elements they incorporate. More than that though, alloys can exhibit unique properties that are different to the metals they are made up of, created through the careful combination of different elements. It’s a skilled balancing act, but one that produces huge benefits.
Alloys are, for example, generally harder than pure metals. They are made up of atoms of different sizes, rather than being uniform. This means that the layers of atoms cannot slide over each other easily, making the whole alloy much stronger than any of the pure metals that the alloy contains in isolation. Alloys also tend to have better corrosion resistance than pure metals, and are more versatile for manipulating into different forms.
The benefits of INCONEL alloys
Alloys are specifically crafted to enhance the properties of the metals and elements they contain, as well as to engineer specific characteristics. The nickel alloys that Corrotherm stocks are all good examples of how the different combinations of component elements creates attractive properties that serve the oil and gas industry.
For example, the popular INCONEL alloy 625 offers high strength, excellent fabricability and outstanding corrosion resistance. These desirable properties are due to the combination of elements that make up the alloy as a whole. As well as nickel and chromium, which together form a strong, versatile and resistance base, this alloy adds in molybdenum and niobium, a potent combination that gives very specific advantages. They distort the alloy’s atomic matrix, resulting in extremely high strength without the need for deliberate strengthening heat treatments.
The alloy gives superior resistance to a wide range of severe, corrosive environments – including the collection of sour gas – to an extent that no single component part could deliver on its own. This alloy can be used in the oil and gas industry across many applications, as it is so versatile. It has been used for pipelines for gathering sour gas, seawater heat exchangers in refineries, power plants and offshore topside services.
Another INCONEL alloy that has attractive properties due to the combination of its elemental components is INCONEL alloy C-276. This nickel alloy is well known for its exceptional corrosion resistance, even in the most aggressive of environments. This is in part achieved by the high molybdenum content, which constitutes 15-17% of the overall makeup.
Molybdenum helps to give the alloy resistance to localised corrosion, such as pitting. INCONEL alloy C-276 also includes a controlled amount of tungsten (3-4.5%). Tungsten has a number of useful properties that can be of benefit to nickel alloys. For example, it has the highest melting point of any pure metal and is incredibly strong. It is added to alloys to increase their overall strength, resistance to wear and tear, and improve corrosion resistance.
This combination of elements makes INCONEL alloy C-276 useful in the oil and gas industry, where high temperatures and extremely corrosive materials are present.
Advantageous alloys in the INCOLOY range
INCOLOY alloys are leaner nickel versions of the INCONEL range. However, they still need to perform in corrosive environments and in high temperatures. This is why the combination of elements within each alloy is so important to achieve the required properties demanded by applications within the oil and gas industry.
INCOLOY alloy 825 is a popular choice for oil well and gas gathering pipes. Its carefully controlled composition gives it the necessary resistance to these kinds of corrosive environments. While there is less nickel than in an INCONEL alloy (38-46%), it is enough to give good resistance to chloride-ion stress-corrosion cracking. Combined with the molybdenum (2.5-3.5%) and the copper (1.5-3%), the nickel also helps to give resistance to sulfuric and phosphoric acids. The molybdenum itself is included to help with resistance to pitting and crevice corrosion, and the titanium (when heat treated) stabilises the alloy against sensitisation to intergranular corrosion. The high chromium content (19.5-23.5%) helps with resistance to nitric acid, nitrates and oxidising salts.
The advanced super-austenitic stainless steel INCOLOY alloy 27-7MO is employed in oil field extraction. Despite its more economical price, this alloy still relies on a combination of elements to give it corrosion resistance, high strength and good fabricability. The inclusion of molybdenum (6.5-8%), chromium (20.5-23%) and nitrogen (0.3-0.4%) helps to resist pitting and crevice corrosion. The nickel (26-28%) also increases resistance to reducing media and, along with the nitrogen, helps with resistance against stress corrosion cracking and attack by caustic media. The chromium also resists against oxidising media. This gives the alloy good performance in mixed acid environments, which is useful in the oil and gas industry.
In the oil and gas industry, where high temperatures and corrosive environments are expected, no one pure metal would offer the blend of properties needed to manufacture parts that can withstand everything that is thrown at it. It is up to the project manager and design engineer to research in detail the different properties that each alloy can deliver to find the right blend for their requirements.
To find out more about the alloys that Corrotherm can supply and their key properties, contact our experienced Sales team.
If you want to learn more, please visit our website Aluminium Casting Flux.