6.1 General
Hot-rolled steel plate and strip are produced by a process that involves heating and rolling to achieve the desired shape and properties. The process involves the following steps:
6.1.1 Heating
The steel plates and strips are heated to a temperature of around 1000℃ in a furnace. This is to increase the plasticity of the steel and allow it to be more easily rolled into the desired shape and thickness.
6.1.2 Rolling
The heated steel is then rolled into shape and thickness on a rolling mill. This process is usually done in a series of stages, with each stage having a different roll diameter and gap width to achieve the desired shape. The roll diameter and gap width can also be adjusted to produce thinner or thicker plates and strips depending on the required thickness and size.
6.1.3 Additional Processing
Once the plates and strips have been rolled to their desired shape and thickness, they may go through additional processing depending on their intended application. These additional processing steps can include annealing, pickling, tempering andgalvanization.
6.2 Standards
Hot-rolled steel plate and strip are regulated by the national standards set out by GB 709-88. The standards ensure all hot-rolled products produced in China meet certain quality and safety criteria, and that the products have a uniform thickness throughout. The standards cover requirements for the size, shape, quality, strength and composition of the steel to ensure the products meet the necessary requirements and expectations.
6.3 Advantages
Hot-rolled steel plate and strip are widely used in many different industries, primarily because of their versatility and cost-effectiveness. They also have many other advantages such as:
• They can be produced in a wide range of sizes and thicknesses, making them suitable for a range of different applications.
• They are generally much more cost-effective than other types of steel products.
• The rolling process helps to remove any internal flaws and stress points in the steel, making the plates and strips even stronger and more durable.
• They can be easily adjusted during the rolling process to produce thinner or thicker plates and strips to meet the exact requirements of the customer.
• Hot-rolled steel products are generally much easier to work with than other types of steel products as they can be easily cut and bent into the required shape.
6.4 Disadvantages
Despite their many advantages, there are a few potential drawbacks associated with hot-rolled steel plate and strip. These drawbacks include:
• Hot-rolled steel products can be more difficult to weld than cold-rolled steel products.
• Hot-rolled products are generally more prone to rust than other types of steel products.
• The surface of the hot-rolled steel plates and strips can be uneven, which can have an impact on the appearance of the finished product.
• Hot-rolling can cause stress points within the steel, which can reduce the strength and durability of the product.
6.5 Applications
Hot-rolled steel plate and strips can be used in a wide range of applications, including:
• Structural components such as beams and columns.
• Automotive parts such as chassis and body panels.
• Shipbuilding components such as hulls and decks.
• Building construction, such as roofing and flooring.
• Machinery components such as cogs and pulleys.
• Pressure vessels and pipes.
• Tools such as knives and saws.
• Sporting goods such as bicycles and golf clubs.
