Comparison of steel grades in the world - hardenable alloy structural steel

World Steel Numbering System for Quenched and Tempered Alloy Structural Steel

Steels with a higher strength or hardness than low or medium carbon steels are normally created through a process of quenching and tempering. Quenched and tempered alloy structural steels are used in a variety of industries, from construction to fabrication, engineering and automotive. The primary use of these materials is to provide higher strength and durability in load bearing components.

Steelmakers classify steels for use in different alloys and strength groups. The World Steel Numbering System (WSN) is used as a way to organize and identify different quenched and tempered alloy structural steels. It is a system of seven-digit coding developed by the International Iron and Steel Institute (IISI) and is the international standard generally used to gain a further understanding of the composition of the material.

The World Steel Numbering System is based on the AISI-SAE-ASTM classification system and is divided into five segments. The first three digits represent the type of steel, while the fourth and fifth digits represent the specific alloy and the strength group. The last two digits are used to identify the trace elements present in the steel.

The first digit of the WSN classifies the type of steel in the following way:

1: Carbon Steels

2: Alloy Steels

3: Tool Steels

4: Stainless Steels

5: Heat Resistant Steels

6: High-Strength Low-Alloy Steels

7: Non-Age-Hardening Low-Alloy Steels

8: Nickel Steels

9: Non-Heat Resistant Low-Alloy Steels

The second two digits of the WSN classify the grade, alloy, and strength group into nine categories:

11: Mild Steels

12: Medium Carbon Steels

13: High Carbon Steels

21: Alloy Steels

22: Cr-Mo Alloy Steels

23: Nickel Chrome Steel

31: Tool Steels

32: High Speed Tool Steels

33: Cold Work Tool Steels

The second two digits of the WSN also identify specific alloy elements, such as chromium, molybdenum, vanadium, and other trace elements. These digits may be followed by an additional two digits, which indicate the specifics of the trace elements.

For example, an alloy quenched and tempered steel with a WSN of 414023 would represent a Cr-Mo alloy steel with 0.24% – 0.33% carbon, 0.55% – 0.9% manganese, 0.17% – 0.37% silicon, 0.4% – 0.7% chromium, 0.8% – 1.1% molybdenum, and 0.25% – 0.35% vanadium.

The WSN is used to classify steel components by their strength and hardness. In general, the higher the WSN (the higher the strength and hardness), the better the performance of the component.

Understanding the WSN system is essential for specifying the correct type of quenched and tempered alloy steel for any given application. By understanding these numbers, engineers can better match the steel grade to its use in a given situation, based on its alloy composition and strength group. Different types of quenched and tempered alloy steels are used for a variety of applications for a variety of components, and the WSN system is the best way to ensure that the correct grade of steel is chosen.

Structural steels are alloy steels with a minimum yield strength of 436 MPa or higher, mainly used in construction and engineering. Alloy structural steels are divided into two categories: low alloy structural steels and high alloy structural steels. According to their chemical compositions, the world steels for structural use have corresponding steel numbers. This article will give an overview of the world steel numbers for structural steels and the chemical composition of the corresponding steel grades.

The common structural steel grades in the world are: S185, S235, S275, S355, S450 and their corresponding steel numbers (1.0035, 1.0038, 1.0050, 1.0060, 1.0070). The American ASTM A36 steel and ASTM A590 steel are equivalent to these steel grades, respectively. Also, the world stainless steel No. represents the corresponding stainless steel grades for structural use. For example, the steel No.1.4309 represents the duplex stainless steel grade S32101, the steel No. 1.4301 represents the austenitic stainless steel grade S30400, and the steel No.1.4016 represents the ferritic stainless steel grade S42900.

In addition, the world quenched and tempered alloy structural steel has a corresponding steel number and chemical composition. For example, the world steel No. 51CrV4 represents the quenched and tempered alloy steel grade 51CrV4, which belongs to the quenching and tempering category of alloy structural steel and its chemical composition is C:0.50%- 0.60%, Si:0.20%- 0.40%, Mn: 0.60%-1.00%, P: < 0.025%, S: < 0.020%, Cr: 0.80%-1.10%, V: 0.10%- 0.15%, Mo: 0.03%-0.10% and Cu: 0.30%.

In conclusion, this article has briefly introduced the world steel numbers for structural steels, low alloy structural steels and quenched and tempered alloy steels, as well as the chemical composition of the corresponding steel grades. In the production and use of structural steels, it is necessary to have a correct understanding of the steel numbers for structural steels and to select the appropriate steel grade for different applications according to their specific requirements.