Materials used for manufacturing at an industrial level need to be highly durable and stable against environmental agents.
Two standard ones used in this regard are stainless steel and galvanized steel; let’s look at these materials side-by-side so you can choose the right one for your project.
Galvanized Steel vs. Stainless Steel – An Overview.
Regular steel alloy is not very corrosion-resistant, creating the need for more chemically stable alloys. If you want to upgrade your regular steel to make it more chemically unreactive, and stable, you can galvanize it or alter its composition to make it stainless.
To make your steel stainless, you’ll have to add alloying agents like chromium. These develop a protective oxide layer on the surface of the steel, which provides corrosion resistance. Other corrosion-resistant elements like molybdenum and nickel can enhance this property.
You can also galvanize your steel to protect it with the help of zinc. Here, you cover the exposed parts of steel up by either electroplating or dipping it in the molten metal.
Both technologies aim to improve steel’s corrosion resistance. Let’s discuss in detail how their properties, health and safety, cost, and applications compare.
Differentiating the Characteristics of Galvanized and Stainless Steel.
These materials differ in their physical and chemical properties. Here’s how:
- Corrosion Resistance: Chromium is distributed evenly in stainless steel. it naturally reacts with oxygen to form an inert oxide layer on it which protects it from corrosive forces.
Galvanization utilizes the fact that zinc is more reactive than iron. So, here, zinc reacts with oxygen first to form a colorless oxide coating, protecting the iron.
- Heat Resistance: Stainless steel has a high heat resistance and can bear temperatures up to 1500 degrees Fahrenheit, but galvanized steel can degrade at just 400 degrees Fahrenheit.
- Strength and Durability: The strength and durability depend upon the manufacturing process of steel; generally, stainless steel is more durable.
- Aesthetic Appearance: Stainless steel is bright, shiny, and mirror-like. And galvanized steel has a dull, gray look.
A Comparison of the Pricing of Stainless and Galvanized Steel.
The cost of these materials depends on several factors.
Generally speaking, stainless steel is pricier due to its alloying materials and higher production and machining cost – it can be 4x as pricey as galvanized steel. Stainless steel also has a higher fabrication expense, but it has lower maintenance expenses.
However, you should factor in the long-term cost analysis.
Stainless steel costs more upfront, but using it for the long term will save you costs. It is durable and doesn’t require frequent replacements, and also costs less in maintenance.
On the other hand, galvanized steel is less durable and has higher maintenance expenses, although it requires a lesser initial investment. This makes it more cost-effective for simpler, short-term applications.
A Comparison of the Applications of Stainless and Galvanized Steels
You commonly use stainless steel for architectural and decorative applications as it is shiny and mirrorlike. As it is easy to maintain and clean, you prefer it for food processing, kitchen utensils, and medical devices. Its heat and chemical resistance makes it ideal for the aerospace and chemical industries.
You generally use galvanized steel for HVAC pipes and automotive parts as it is easier to machine and fabricate. As it has more color variation due to its ability to react with colorant materials and is cheaper, you prefer it for outdoor furniture. You also use it for electrical conduits and fittings.
Comparing the Ease of Maintenance of Stainless Steel and Galvanized Steel.
Stainless and galvanized steel require different maintenance practices. For stainless steel, you require less maintenance. You must clean it regularly, store it in a dry area without harsh chemicals, and thoroughly remove stains.
In comparison, galvanized steel requires more extensive maintenance. You must regularly clean and store it somewhere safe and protect the zinc coating, which wears off over time. Constantly check for damage to the coating and apply protective paint to delay the wear process.
Corrosion Resistance Comparison of Stainless and Galvanized Steel.
Corrosion is a chemical reaction between steel, oxygen, and moisture. The iron inside reacts with oxygen and moisture to form oxides which weaken it over time.
Stainless steel is incredibly corrosion-resistant due to its chromium content. It forms an oxide layer, which blocks oxygen access to the steel surface. However, it can corrode in harsh environments or if it is scratched, which means its passive oxide layer is damaged.
Galvanized steel is also stable in this regard. The zinc on it forms an oxide instead of letting iron react with oxygen, protecting the steel’s integrity. However, this transparent zinc oxide layer wears off over time due to environmental factors. This exposes the steel completely, so you’ll have to get a new coating after a while.
Durability Comparison of Stainless and Galvanized Steel.
Both these materials have excellent durability.
SS contains highly durable materials, like chromium, nickel, and molybdenum, that increase its strength and hardness and let it resist high temperatures. Martensitic stainless steel, in particular, is known for its high durability.
Galvanized steel is also durable. However its oxide layer wears off over time, and the steel under it can not protect itself against environmental agents. This affects the material’s longevity.
Comparing the Strength of Stainless and Galvanized Steel.
Stainless steel has a high tensile strength ranging from 50,000 to 300,000 psi. The exact value depends upon its chemical composition and steel grade. But in general, the material is strong and can handle different types of stress.
Galvanized steel is also very strong thanks to its zinc coating, and its tensile strength ranges from 50,000 to 80,000 psi. This is at par with low-strength stainless steel but significantly less than high-strength stainless steel.
How do Stainless Steel and Galvanized Steel Look?
The appearance of steel is essential in different applications, such as architecture and furniture. Different surface finishes can enhance the looks of steel.
Stainless steel is shiny and gray. It has a smooth, polished finish giving it a modern and sleek look. You can create different appearances on stainless steel with surface finishes, including matted, brushed, or patterned.
Galvanized steel just has a simple, dull matte gray appearance; people prefer stainless steel more when aesthetics are a concern.
Fabrication Comparison of Stainless Steel and Galvanized Steel
Fabrication refers to how easy it is to mold or shape the material in different parts.
Stainless steel is tough and strong, making it challenging to fabricate. It cannot easily be cut, drilled, or milled because its machinability is low – you require specialized equipment and practice to machine it.
Using metalworking lubricants can reduce the friction between the machine and the steel, making fabricating stainless steel somewhat easier.
In comparison, galvanized steel is softer. So, it’s more machinable and formable: you can easily cut, drill, or mill it with standard fabrication methods. And you don’t need specialized equipment or practices to fabricate it either.
You can use different welding and joining techniques for stainless or galvanized steel. However, galvanized steel is comparatively more convenient to weld. You can weld it through standard welding techniques like arc welding.
Stainless steel has a high thermal conductivity, making it prone to distortion and warping in the welding process. It is less convenient to weld than galvanized steel. However, you can weld it using pre- and post-weld treatments to reduce cracking and distortion.
You require specialized techniques like TIG or MIG to weld stainless steel.
Availability Comparison of Stainless Steel and Galvanized Steel.
Stainless steel is more widely available than galvanized steel: it is produced in larger quantities as it is more common. However, its availability depends upon its grade – rarer grades are less readily available. This material also has a shorter lead time and production schedule.
You can find galvanized steel readily too; however, its availability may be limited in some geographical locations or markets with low demand. Its lead times and production schedules are also longer.
Health and Safety Comparison of Stainless Steel and Galvanized Steel
Both these materials are considered low-risk.
The health and safety of stainless steel depend upon its manufacturing process. Exposure to welding fumes or metal dust can be hazardous to industry workers. So, you must follow industrial safety practices when working with stainless steel. These practices include proper ventilation and wearing personal protective equipment.
As stainless steel is heavy, lifting it improperly can be a health hazard and cause injury and posture issues.
Similarly, galvanized steel is also a safe material with some hazards. Zinc fumes or dust are released in the galvanization process, which can damage your health if inhaled. So, you should perform galvanization only in well-ventilated places and with personal protective equipment. Sharp galvanized steel pieces can also cause cuts and wounds.
Suitability for Food Contact Comparison of Stainless Steel and Galvanized Steel
In the food processing industry, you must be careful when choosing equipment materials. They must be suitable for food contact.
Stainless steel is suitable for food contact. It is corrosion-resistant and easy to clean, and food acids and alkalis do not damage stainless steel. It also does not pose any risk of metal leaching.
Galvanized stainless steel is not suitable for the food industry. It has the risk of zinc metal leaching, a severe health hazard that can cause neurological issues. Zinc also readily reacts with acid and makes harmful products. Galvanized steel is also less easy to clean, which can promote bacterial growth.
Comparison of Outdoor Use of Stainless Steel and Galvanized Steel
Stainless steel is an excellent outdoor material used in signages and street furniture. Many stainless steel grades are weather resistant and can withstand temperature extremes, high humidity, and sunlight. They are also significantly easier to clean and require little maintenance, so your outdoor furniture will look fresh and pristine for years with proper maintenance.
Galvanized steel is also commonly used for outdoor furniture. It is also an excellent choice for outdoor use but is less corrosion and weather resistant than stainless steel. So, you must make the necessary rust prevention and treatment strategies. This includes frequently checking for any damage to the zinc coating and replacing it as soon as you see the damage. Because of this, outdoor galvanized steel furniture requires more maintenance.
Comparison of Indoor Use of Stainless Steel and Galvanized Steel
Stainless and galvanized steel has widespread indoor uses but differs in their applications.
The indoor use of stainless steel is mainly in kitchen appliances which make contact with food and require frequent cleaning. As stainless steel is biocompatible and easy to clean, it is a popular material choice for kitchen utensils. Its aesthetic appeal also makes it a good material for countertops.
Galvanized steel is used where you prefer flexibility and machinability. You commonly find it in light fixtures and HVAC pipes.
Environmental Impact of Stainless Steel vs. Galvanized Steel
Stainless steel and galvanized steel have different carbon footprints and leave different environmental impacts as they use different manufacturing technologies. The life cycle assessment of steel determines the environmental impact of each steel type from its raw metal extraction to its end-of-life.
You require an electric arc furnace to heat and melt stainless steel materials at a high temperature, which requires a lot of energy. In many steel plants, this energy comes from burning fossil fuels and leaves a high environmental impact.
You also require a lot of energy for galvanized steel production as you have to melt zinc. So, zinc production also generates greenhouse gases. It also produces waste acid, which you must treat before disposal.
However, the emissions produced in stainless steel manufacturing are far more than those produced in galvanized steel manufacturing.
Stainless and galvanized steels are highly recyclable and sustainable, but stainless steel is more sustainable as it is more durable and produces less waste. You also have to remove all traces of zinc before you recycle galvanized steel which requires significant energy.
Conclusion
Stainless steel is an alloy of steel with a high proportion of chromium, while galvanized steel is steel with a zinc coating. Both materials are mainly used for their ability to withstand corrosive forces.
Stainless steel is significantly more costly than galvanized steel. But it is readily available and has higher corrosion resistance, durability, and strength. It is also safer for use in the food industry and requires less maintenance. Its sleek look is also aesthetic; however, it is less easy to fabricate.
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FAQs
1.How do you manufacture galvanized steel?
Galvanized steel is manufactured in two ways. One method is immersing steel in molten zinc to get your coating; and the other method is electroplating, in which you deposit zinc on steel through electrochemical means. The zinc layer made through electroplating is thinner.
2.Which types of steels can you galvanize?
You generally galvanize carbon steel to make it more corrosion-resistant. Theoretically, you can even coat stainless steel with zinc, but it is not recommended. The temperature you dip steel in the zinc coating is too high and can warp melt stainless steel.
