The hardness of DC01 cold-rolled steel sheet (typically in the range of 100-140 HV or 60-80 HRB) is a key indicator of its mechanical properties, directly impacting its machinability, formability, and usability. When selecting an application, it's important to consider the hardness characteristics in conjunction with specific requirements. This can be analyzed from the following perspectives:
1. Core Characteristics Based on Hardness: The "Low Hardness - High Ductility" Balance
DC01's hardness is low to medium, corresponding to its "general forming grade" positioning. Its core advantages are good ductility and low machining resistance, while its strength and wear resistance are moderate. This characteristic makes it more suitable for applications requiring high machinability but less demanding high hardness and wear resistance. II. Suitable Applications (Matching Hardness Characteristics)
1. Simple Forming
Reasons: Low hardness means the steel sheet has good plasticity and low yield strength, making it less susceptible to cracking during bending, folding, and shallow drawing processes. Furthermore, low external forces are required during processing (e.g., low stamping die load).
Specific Applications:
Home appliance housings (e.g., washing machine panels, refrigerator linings): These require simple bending and forming, requiring high surface flatness. Low hardness prevents cracking or wrinkling after processing.
Daily hardware (e.g., lampshades, brackets, trays): These are often formed by shallow stamping or shearing and do not require high loads. Low hardness reduces processing difficulty.
2. Non-stressed or low-load structural parts
Reasons: Medium hardness, low tensile strength and yield strength (270-410 MPa), prevents them from withstanding severe impact or high loads, but are sufficient for static, low-stress applications.
Specific Applications:
Automotive interior parts (e.g., instrument panel frames, seat rail covers): These do not require structural stress, and low hardness facilitates the stamping of complex shapes. Packaging containers (such as metal cans and storage boxes): The primary requirements are formability and sealing. Low hardness reduces the risk of brittle fracture during processing.
3. Applications requiring secondary processing
Reasons for suitability: At low hardness, steel plates can undergo secondary processing such as welding, drilling, and grinding, and are less susceptible to tool wear or weld cracking caused by high hardness.
Specific applications:
Machinery protective covers and equipment casings: These require on-site cutting, welding, and assembly. Low hardness reduces tool wear and improves efficiency.
Simple metal brackets: These require bending or drilling according to installation requirements. Low hardness with good plasticity prevents breakage during processing.
3. Applications to avoid (conflicting with hardness):
Applications requiring high wear resistance: Applications such as gears, bearings, and conveyor belts. DC01 has a low hardness (≤140 HV) and the surface is easily worn and cannot withstand long-term friction. Therefore, high-hardness steel plates in the quenched state (such as case-hardened steel or spring steel) should be selected. For high-load or impact applications, such as automotive chassis components and engineering robot arms, DC01 lacks strength and hardness, making it prone to deformation or fracture under stress. Therefore, high-strength low-alloy steel (such as HSLA steel) is recommended.
For precision forming applications (such as deep drawing), while DC01 exhibits good ductility, cold-rolled steel sheets with higher ductility (such as DC04 and DC06) are more suitable for deep drawing (e.g., for can bodies). These cold-rolled steels have higher work hardening exponents (n values), reducing the risk of tensile cracking.
Summary
DC01's hardness characteristics (low to medium hardness and high ductility) limit its core applications to simple forming, low loads, and applications requiring secondary processing, such as home appliances, automotive interiors, and household hardware. When selecting a material, it's important to carefully consider the processing method (forming difficulty) and the load conditions (load magnitude). Avoid using it in applications with high wear resistance and high loads to maximize its advantages of ease of processing and low cost.