SPCC Tensile Strength
SPCC is cold-rolled low-carbon steel plate (JIS G 3141 standard). Its tensile strength (Rm) is an important indicator of a material's resistance to tensile fracture. Detailed data and influencing factors are provided below:
1. Standard Tensile Strength Range (JIS G 3141)
Condition Tensile Strength (Rm) Remarks
Annealed (Soft) 270-370 MPa: Good ductility, suitable for deep drawing
Hard (Unannealed) 340-410 MPa: Higher strength, slightly poorer formability
China GB/T 5213 ≥270 MPa: Basically consistent with the JIS standard
Note:
Tensile strength is affected by material thickness. Thin plates (e.g., 0.5 mm) may be closer to the lower limit, while thick plates (e.g., 2.0 mm) may be closer to the upper limit.
Annealing reduces strength and increases elongation (making it more suitable for stamping).
2. Relationship between Tensile Strength and Thickness (Reference Values)
Thickness (mm) Typical Tensile Strength (MPa)
0.3-0.5 270-320
0.6-1.0 300-350
1.2-2.0 330-380
>2.0 350-410
Data Source: JIS G 3141 and technical data from common manufacturers (e.g., Baosteel and Nippon Steel).
3. Tensile Strength vs. Other Mechanical Properties
Relationship between Performance Indicators and Tensile Strength
Yield strength (Rp0.2) is typically 50%-70% of tensile strength (approximately 140-250 MPa).
Elongation (A50mm): Lower tensile strength corresponds to higher elongation (up to 30%-40% in the annealed state).
Hardness (HRB): Higher tensile strength corresponds to greater hardness (HRB 40-75).
4. Factors Affecting Tensile Strength
Annealing:
Annealing refines the grain size and reduces tensile strength (270-340 MPa), but improves ductility.
Unannealed hard SPCC has higher strength (340-410 MPa), but is susceptible to cracking during stamping.
Cold Rolling Work Hardening:
The greater the cold rolling deformation, the higher the tensile strength (but the elongation decreases).
Chemical Composition:
Increasing carbon (C) content increases strength, but the carbon content of SPCC is limited to ≤0.12%, resulting in lower strength.
5. Recommended Selection for Practical Applications
For applications requiring high formability (e.g., deep drawing): Choose annealed SPCC (tensile strength 270-340 MPa).
For applications requiring higher strength (e.g., structural parts): Choose hardened SPCC (tensile strength 340-410 MPa) or switch to SPCD (stamping steel).
For rust prevention: Choose SECC (galvanized SPCC), which offers similar tensile strength but offers improved corrosion resistance.
Summary
The tensile strength of SPCC is typically 270-410 MPa, depending on the material condition (annealed/hardened) and thickness. In sheet metal processing, the appropriate grade and treatment process should be selected based on the degree of stamping difficulty and strength requirements.
