Difference Between Cold Rolled Steel and Galvanized Steel

Both cold rolled steel and galvanized steel are popular in a variety of applications. They are very similar. But considering their different production methods, they also have many different features and applications. Keep reading for more details!

Differences in Production Process

Cold rolled steel (CRS) uses hot rolled coils as material. It is obtained by continuous rolling at room temperature (under recrystallization temperature) after pickling to remove the oxide scale. Due to the cold hardening caused by continuous cold deformation, the strength and hardness of the coil rolled steel increase, and the toughness and plasticity decrease. While galvanized steel (GI) often uses cold rolled steel or hot rolled steel sheets as base metal, then a layer of zinc is applied on the surface by hot-dip galvanizing or electro-galvanizing to enhance the corrosion performance of the base metal.

Different Anti-Corrosion Performance

As mentioned above, the galvanized steel is protected with a layer of zinc coating. So it has better corrosion resistance than cold rolled steel. Accordingly, a GI steel product has a longer lifespan than a CR steel product under the same circumstance.

Mechanical Property Difference

In fact, the zinc layer on the GI surface will not change the mechanical properties of the substrate. The mechanical properties of cold-rolled steel and GI steel are very similar. Therefore, they can be cut, punched, welded, and processed. But the ductility and weldability of cold rolled steel are better than that of galvanized steel. Below is a table showing their mechanical properties.

Material Grades	Cold Rolled Steel	Hot Dipped Galvanized Steel	Mechanical Properties
High Strength	G550	G550	Tensile strength ≥570MPa Yield strength ≥550MPa
Deep Drawing	SPCESPCEN	SGCE/DX52D/53D	Tensile strength≥260MPa Yield strength: 180-260MPa Elongation: 36-38%
General Use	SPCC	SGCC/DX51D	Tensile strength ≥270MPa Yield strength ≥280MPa Elongation: 22-36%

Steel Surface

When it comes to appearance, they seem to be similar to some extent, but still have some distinctions. For example, the cold rolled steel has a clean, smooth, and glossy surface, with high precise and close tolerance. It is very similar to electro galvanized steel. As for hot-dipped galvanized steel, it is rough, rugged, dark, and has spangles, including common spangles, big spangles, small spangles, and zero spangles.

In addition, both cold rolled and galvanized steel can be painted to enhance the overall look.

Defects

All products come with cons and pros, including CR and GI steel. But their limitations are different.
Cold rolling limits the size and thickness of the finished CR steel products (usually the thickness is less than 4mm). While the only limitation of galvanizing steel is that it cannot be used in high-temperature conditions and in alkaline environments. And if the GI steel surface is scratched, the zinc layer will lose its protection around the breakage.

Usage

When applied to the detailed environment, the typical products made via them include bars, rods, sheets, coils, wires, pipes, and strips. But they are designed for different using purposes actually. Let’s talk about it one by one.
Cold-rolled steel products result in a modern, smooth, and visually appealing surface with precise size. Therefore, they are suitable for applications where tolerances, surface conditions, concentricity, and straightness are factors. Generally, they are versatile in automobiles, construction, electric appliances, furniture, manufacturing, and as the base material of GI and PPGI steel.
On the contrary, galvanised steel products have better protection against corrosion and rust. Therefore, they are better for outdoor and corrosive environments, such as construction, energy, infrastructure, offshore structure, wall & roofing systems, home appliances, etc. You can choose the right steel material for your different applications.

Price

In the steel market, the galvanized steel is more expensive than cold rolled steel due to the extra addition of zinc, and the relatively complex making process. But their final prices will be different with many other factors, such as supplier, location, freight, policy, product size, packaging, etc. When choosing, remember not to focus on price only. You can take supplier, product quality, customer service, and communication into consideration. Believe that they can contribute to your work a lot.

Which One is Right for Me?

When choosing between the cold rolled and galvanized steel, it is important to have a general understanding of them. More than that, you should talk to a professional to optimize your projects. Wanzhi Steel can be your first potential partner. We are a reliable steel supplier from China, manufacturing a range of metal products that include carbon steel (hot/cold rolled), galvanized steel, galvalume steel, and stainless steel. With more than 20 years of experience, we have abundant product knowledge accumulation and professional service teams, having served more than 1000 customers from different countries. Welcome to cooperate with us and order from our warehouse!