The Development Situation of Alloy Structural Steel

Introduction

The development of alloy structural steels has enabled them to become the main materials applied in modern engineering and mechanical manufacturing due to their excellent properties of strength, toughness, weldability, and tensile strength. Alloy structural steels, compared with other types of steels, also have superior corrosion resistance and hot and cold formability. These properties make alloy structural steel a core mateial in numerous fields.

Overview of Alloy Structural Steel

Alloy structural steel is an alloy-based iron-carbon alloy, and its carbon content ranges from 0.1% to 1.5%. It is a low-carbon steel, and its main alloy components include copper, chromium, nickel, molybdenum, tungsten, vanadium, and manganese. In the alloy steel, the total content of alloying elements is generally below 5%. Various alloying elements are added to the low-carbon steel, to increase strength, toughness, plasticity, and other properties.

The development of alloy structural steel can be divided into three stages.

The first stage, before 1960s, was the initial stage of alloy structural steel. At this stage, technology was relatively backward and the performance of alloy structural steel was also relatively low. The widely used alloy structural steels were low-alloy steel, medium alloy steel, high-alloy steel and special alloy steel. It was mostly used in the manufacturing of components such as springs and tools.

The second stage, from 1960 to 1990, was the middle stage of development of alloy structural steel. At this stage, the alloying element content of low-alloy steels was increased, and new alloy structural steel grades were developed by adding elements such as manganese, nickel, chromium, and molybdenum. This stage was characterized by the emergence of high-strength, corrosion-resistant alloy structural steels. It was also of great significance in the development of high-strength and corrosion-resistant alloy structural steels.

The third stage, after 1990, was the advanced stage of alloy structural steel development. At this stage, modern alloy structural steel and special alloy structural steel have been developed by adding more alloying elements. The most significant contribution was the development of high-performance alloy structural steels and ultra-high-performance alloy structural steels. These steels provide high strength, good weldability, and excellent resistance to corrosion, and have become the main materials used in large-scale engineering and machinery manufacturing.

Application of Alloy Structural Steel

Due to its excellent performance, alloy structural steels are widely used in various engineering and machinery manufacturing fields.

1. Automotive Industry

Alloy structural steels are widely used in the automotive industry, with engineering steels such as SAPH440, SCO440, SAPH370, SCR420, and SCR440; high-strength steels such as SM570 and SM490; and special alloy structural steels such as SCM 430, SCM440 and SCM435. These steels are mainly used in the manufacture of automotive chassis, body components, suspension and transmission parts.

2. Construction Industry

In the construction industry, alloy structural steels such as S275, S355, S420, S460, S500, and S550 are widely used in the manufacture of buildings and bridges.

3. Shipbuilding Industry

In the shipbuilding industry, alloy structural steels are widely used in the manufacture of hulls. Commonly used steels include AH36, DH36, EH36, FH36, and AH32.

4. Oil & Gas Industry

In the oil and gas industry, alloy structural steels including 16Mo3, 15Mo3, 13CrMo4-5, A387, P11 and P22 are widely used in the manufacture of pressure vessels, boilers, and pipelines.

Conclusion

In conclusion, the development of alloy structural steels is a great contribution to the development of the engineering and machine manufacturing fields, due to the excellent properties of strength, toughness, weldability, and tensile strength. Alloy structural steel has become the main material applied in modern engineering and machinery manufacturing, and will continue to be used in the future.

Alloy structral steel, developed from ancient times to the present, is an indispensable engineering material. The development of alloy structral steel makes the quality of engineering materials gradually improve and new technology applied continuously.

With the progress and application of modern manufacturing technology, alloy structral steel has been used productively in bridge struction, buildings, machinery and other engineering fields. In todays word, the most important component in alloy structral steels are high-carbon steels whose carbon content are extremely high. It has excellent strength and wear resistance properties. In addition, many alloys of alloy structral steel contain various metal components, such as nickel, molybdenum and chromium, which also significantly improve its mechanical properties.

Moreover, with the breakthrough of nanomaterials and metal materials technology, the development of alloy structural steel has been rapid in these years. Its features such as high strength, hard wear resistance, corrosion resistance, thermal and chemical stability have improved significantly, and its application fields have become wider and wider.

To sum up, the development of alloy structural steel is an important process in the history of modern science and technology. In the future, the alloy structure steel will have a wider development trend with improved performance and better application fields.