When approaching your project, it is crucial to know the type of steel that is best suited for your needs. Different types of steel manufacturing can produce material that performs better for the specific applications. The hot and cold rolled steel manufacturing methods specifically have a great effect on the overall performance of the steel.

Prior knowledge of distinctions between the two methods can help your company save on time, raw material cost, and additional processing. This article aims to explain the differences between hot and cold rolled steel and discuss the advantages (and limitations) of each.

NOTE: Hot-rolling and cold-rolling should not be mistaken for different grades of steel. Steels of different grades can be produced as hot-rolled or cold-rolled.

HOT-ROLLED STEEL

Hot-rolling refers to a mill process in which you roll the steel at a temperature above its recrystallization temperature; a heat that typically exceeds 1000° F.

When steel is heated past its recrystallization point, it becomes more malleable and can be properly formed and shaped. It also allows for the ability to produce larger quantities of steel. The steel is then cooled at room temperature, which “normalizes” it, eliminating the worry for stresses in the material arising when quenching or work-hardening.

When the steel cools off, it will shrink non-uniformly, which gives slightly less control on the overall size and shape of a finished hot-rolled product.

Hot-rolled steel typically has a scaly surface finish. For situations in which the appearance of the material is a concern, the scales can be removed by several techniques: pickling, grinding, or sand-blasting.

These properties make hot-rolled steel most suitable for structural components and other applications where incredibly precise shapes and tolerances are of less importance, such as:

• Railroad tracks
• I-beams
• Agricultural equipment
• Sheet metal
• Automotive frames

COLD-ROLLED STEEL

As you might suspect, the manufacturing process behind cold-rolled steel is a bit different. Despite the name, this process refers to steel that is pressed with the pressure of a roller at room temperature.

Compared to hot-rolled steel, cold-rolled steel has a nearly 20% increase in strength through the use of strain hardening. It’s through a series of breakdown, semi-finishing, sizing, semi-roughing, roughing, and finishing that cold-rolled steel shapes can be created.

Cold-rolling steel allows for the creation of very precise shapes. Since the process is performed at room temperature, the steel will not shrink as it cools, as it does in the hot-rolled process.

The exterior finish of cold-rolled steel is very desirable when aesthetics and visual appeal are a priority in your project.

However, the applications of cold-rolled steel are somewhat limited to a couple of shapes – square, round, flat, and variations thereof.

Typical uses for cold-rolled steel:

• Strips
• Bars
• Rods
• Home appliances
• Roof and wall systems
• Metal furniture
• Aerospace structural members

HOT AND COLD ROLLED STEEL. WHICH DO I NEED?

If you require large structural components, you will most likely need the hot-rolled steel process to create the parts. For smaller parts that require more precise and durable qualities, then the cold-rolled steel process is the way to go. If you have questions about […]

Today, the currently operating U.S steel industry includes approximately 100 steel supply and steel production facilities, employing 140,000 people, directly or indirectly supporting the livelihood of almost 1 million Americans. AHSS (Advanced high-strength steel) is the only material that reduces greenhouse gas emissions in all phases of an automobile’s life: manufacturing, driving, and end-of-life. Being the most recycled material in the world, more than aluminum, copper, paper, glass, and plastic combined, over 60 million tons of steel are recycled or exported for recycling each year in North America alone.

The Rise of The American Steel Industry

Early colonists had 2 primary goals: shelter and food. They needed to build homes, plant crops, and hunt. In order to facilitate these tasks, iron tools were needed. Things like hammers, knives, saws, axes, nails, hoes, bullets, and horseshoes. Iron products were in demand, but it wasn’t until the 19th century, when technological advances drove down the cost and increased the quality of the product, that steel manufacturing became a dominant industry. “With the abundant iron ore deposits around Lake Superior, the rich coal veins of Pennsylvania, and the easy access to cheap water transportation routes on the Great Lakes, the Midwest became the center of American heavy industry,” business and financial historian John Steele Gordon writes in his Importance of Steel exposition.  “In the years after the Civil War, the American steel industry grew with astonishing speed as the nation’s economy expanded to become the largest in the world. Between 1880 and the turn of the century, American steel production increased from 1.25 million tons to more than 10 million tons. By 1910, America was producing more than 24 million tons, by far the greatest of any country.”

Strong technological foundation was the primary driving force behind the tremendous growth in the steel industry. Steel supply was crucial for rapid expansion of cities and urban infrastructure. Railroads, bridges, factories, buildings, and eventually, in the 20th century, steel was used to make household appliances and automobiles. It was at this time that the US steel industry began using the open-hearth furnace, then, the basic oxygen steelmaking process.

Long after World War II, the American steel service industry continued to flourish and serve as the foundation of the national economy. In 1969, American steel production peaked when the country produced 141,262 ,000 tons. Since then, large steel mills have been replaced by smaller mini-mills and specialty mills, using iron and steel scrap as feedstock, rather than iron ore.

American Steel Service and Industry Today

Although we’ve entered the computer age, American steel remains a top competitor in the global marketplace. The United States is the world’s largest steel importer, according to the American Iron and Steel Institute, labor productivity has seen a five-fold increase since the early 1980s, going from an average of 10.1 man-hours per finished ton to an average of 1.9 […]