Carbon hot-rolled round steel for standard parts (GB/715-1989)

Carbon Hot-rolled Round Steel --AGB/715-1989

Carbon hot-rolled round steel is one of the most common and widely used forms of steel due to its versatility and affordability. It has been produced for centuries and is essential in many modern manufacturing processes. The standard for carbon hot-rolled round steel is the AGB/715-1989. This standard is intended to set the requirements and purpose of the steel, and describes the general manufacturing process and finished product specifications.

Carbon hot-rolled round steel is characterized by its high strength and toughness. It is able to withstand thermal shocks, cyclic loading, and other forms of stress that can occur in a variety of applications. The steel also has good weldability, making it suitable for many components in the manufacture of machinery and other products.

The manufacturing process of carbon hot-rolled round steel is defined by the AGB/715-1989 standard. The steel must be formed from a single thermomechanically treated billet into an annular ring. The process begins with the billet being heated in an electric furnace then hot-rolled. The rolled material is then turned, cut, and annealed prior to being cold-drawn and checked for flatness and straightness.

Once the carbon hot-rolled round steel has been produced, it is subject to a series of test and inspection requirements. The standard defines the physical and chemical requirements for the steel, such as its surface quality, mechanical properties, chemical composition, and tensile strength. The tests and inspections are designed to ensure that the finished product meets the requirements and that it is of a given quality.

In general, carbon hot-rolled round steel is an effective and economical material for the manufacture of machinery and other components. Its strength, toughness, and weldability make it an ideal material for many applications. The AGB/715-1989 defines the standards to be followed in the production of the material, guaranteeing a quality product. Those in the metalworking industry should always use the AGB/715-1989 when specifying carbon hot-rolled round steel for their products.

Carbon Hot Rolled Round Steel (GB/715-1989)

The carbon hot rolled round steel produced according to GB/715-1989 is a kind of steel produced by hot rolling and can be used as cold drawn steel in various fields. The product grade of the general specification is S15C, S20C, S25C, S35C, S45C, S50C, S55C and C35, C45, etc.

The chemical composition(%) of carbon hot rolled round steel (GB/715-1989)is given in Table1.

Table1 The chemical composition(%) of carbon hot rolled round steel (GB/715-1989)

Grade C Mn Si S P S15C 0.12-0.18 0.3-0.5 0.15-0.3 ≤0.035 ≤0.035 S20C 0.17-0.23 0.3-0.5 0.15-0.3 ≤0.035 ≤0.035 S25C 0.22-0.29 0.3-0.5 0.15-0.3 ≤0.035 ≤0.035 S35C 0.30-0.38 0.3-0.7 0.15-0.3 ≤0.035 ≤0.035 S45C 0.42-0.50 0.4-0.7 0.15-0.3 ≤0.035 ≤0.035 S55C 0.52-0.60 0.4-0.7 0.15-0.3 ≤0.035 ≤0.035

The mechanical properties of carbon hot rolled steel (GB/715-1989) is shown in Table2.

Table2 The mechanical properties of carbon hot rolled steel (GB/715-1989).

Grade Tensile strength(MPa) Elongation A50mm(%) Impact energy 0-20℃(J) KV2(J) S15C δb≥460 ≥20 ≥49 ≥47 S20C δb≥530 ≥19 ≥62 ≥59 S25C δb≥590 ≥18 ≥75 ≥72 S35C δb≥700 ≥17 ≥99 ≥98 S45C δb≥830 ≥14 ≥131 ≥129 S55C δb≥830 ≥12 ≥156 ≥156

The characteristics of carbon hot rolled round steel (GB/715-1989) are as follows:

1. High hardness and good wear resistance.

2. Can be bent and deformed into different shapes.

3. Good corrosion resistance, less than or equal to 110°C oxidation temperature.

4. Good weldability, no special requirements on welding parameter and process.

In conclusion, carbon hot rolled round steel (GB/715-1989) has good mechanical properties, chemical stability and good welding performance. It is widely used in gear, shaft, piston pin, connecting rod and other standard parts.