Introduction
Steel strips are thin, flat pieces of metal rolled either in a coil or cut to length in varying degrees of hardness, widths, and thickness. The versatile use of steel strips in the manufacturing industry has made them an essential item for an array of applications. Steel strips can be used for packaging, building and architectural projects, car body construction and many other industries. GB/T 3524-92 specifies the requirements, sizes, shapes, weight and tolerance of hot rolled carbon and low-alloy steel strips for general application.
Overview of GB/T 3524-92
GB/T 3524-92 is the national standard for hot-rolled carbon and low-alloy steel strips for general application. It was formulated by the State Quality Supervision and Test Center, which is the national standardization technical committee and the Quality Inspection Center of the Ministry of Metallurgical Industry. The purpose of GB/T 3524-92 is to establish uniform requirements, sizes, shapes, weights and tolerances for hot-rolled carbon and low-alloy steel strips. It is applicable to strips with a thickness of ≤25mm and a width ≤550mm that are hot-rolled and supplied in cut lengths or coil form.
The Requirements of GB/T 3524-92
GB/T 3524-92 contains four chapters and one annex. Chapter 1 covers scope, normative references, definitions and designations, terms and symbols, drawings, packaging, inspection and quality assurance. Chapter 2 sets the requirements for hot-rolled carbon and low-alloy steel strips. These requirements cover the chemical composition, mechanical properties, and size tolerance. Chapter 3 describes the dimensional requirements and tolerances. Chapter 4 outlines the requirements for appearance, surface quality, marking, packing, inspection and quality assurance. The annex lays out the specific requirements and methods for verifying the chemical composition, mechanical properties and quality assurance.
Chemical Composition
In order to meet the requirements of GB/T 3524-92, the chemical composition of the steel strips must fall within certain ranges. The maximum permissible limits for the different components are listed in Table 1. The copper content should not exceed 0.20% and the steel should also contain no more than 0.30% of sulfur and phosphorus.
TABLE 1 MAXIMUM PERMISSIBLE LIMITS OF CHEMICAL COMPOSITION
Component Maximum Content (%)
Carbon (C) 0.12-0.60
Manganese (Mn) 0.30-1.60
Silicon (Si) 0.10-0.60
Phosphorus (P) ≤ 0.030
Sulfur (S) ≤ 0.030
Copper (Cu) ≤ 0.20
Mechanical Properties
GB/T 3524-92 establishes the mechanical properties that must be attained by the steel strips. These properties must be tested and verified through appropriate methods such as the tensile test and hardness test. Table 2 and Table 3 provide the minimum mechanical properties for hot-rolled carbon and low-alloy steel strips respectively.
TABLE 2 MINIMUM MECHANICAL PROPERTIES FOR HOT-ROLLED CARBON STEEL STRIP
Component Minimum Values
Tensile Strength (MPa) ≥ 350
Yield Strength (MPa) ≥ 235
Elongation (% in 2 in. or 50mm) ≥ 24
TABLE 3 MINIMUM MECHANICAL PROPERTIES FOR HOT ROLLED LOW-ALLOY STEEL STRIP
Component Minimum Values
Tensile Strength (MPa) ≥ 400
Yield Strength (MPa) ≥ 300
Elongation (% in 2 in. or 50mm) ≥ 22
Conclusion
GB/T 3524-92 is the national standard for hot rolled carbon and low-alloy steel strips. It provides a set of requirements, sizes, shapes, weights, and tolerances to ensure the quality of the product. The chemical composition, mechanical properties, and quality assurance requirements of the steel strips must meet the specified limits in order to be compliant with GB/T 3524-92. The standard helps to ensure the quality and safety of the steel strips used in various industries. It is an important benchmark for the production and use of hot rolled carbon and low-alloy steel strips.
