What are the differences in welding performance between SPCC and DC01?
The welding performance of SPCC and DC01 cold-rolled steel plates is identical; there are no essential differences. This equivalence in welding performance stems from the strict alignment of their standards for key factors affecting welding. This can be analyzed from three perspectives: "Core Determinants of Welding Performance," "Performance in Actual Welding Scenarios," and "Common Misconceptions":
1. Core Determinants of Welding Performance Are Identical
Welding performance (such as weld strength, post-weld cracking tendency, and weld toughness) is primarily determined by chemical composition (especially carbon content) and mechanical property matching. SPCC (Japanese JIS G 3141 standard) and DC01 (Chinese GB/T 11253 standard) are fully aligned on these two key indicators, fundamentally ensuring the same welding performance.
Identical performance in real-world welding scenarios.
Whether using common welding processes (resistance welding, arc welding, laser welding) or typical applications (home appliances, hardware, simple automotive parts), SPCC and DC01 offer identical welding performance, eliminating the need to adjust welding parameters based on grade:
1. Resistance welding (most common applications: splicing home appliance housings, spot welding hardware brackets)
Core requirement: Match the welding current and on-time to the base material thickness to avoid "cold welds" or "burn-throughs."
SPCC and DC01 have similar resistivity and thermal conductivity (due to their identical chemical composition). For the same plate thickness (e.g., 1.0mm), the required welding current (e.g., 800-1000A) and on-time (e.g., 15-20ms) are identical, and post-weld weld strength (e.g., pull-off strength) is identical. 2. Arc Welding (Application: Welding thick plate hardware structures, such as distribution box frames)
Core Requirements: Matching welding materials (E43 series electrodes are commonly used for low-carbon steel) and controlling welding voltage and current to avoid post-weld cold cracking.
For both low-carbon steels, using E4303 (J422) electrodes, the welding voltage (e.g., 22-26V) and current (e.g., 100-140A) parameters are fully compatible. The weld hardness (HV ≤ 200) and impact toughness (impact energy ≥ 27J at -20°C) are consistent, with no "DC01 welds are tougher" or "SPCC welds are more prone to cracking" scenarios.
3. Laser Welding (High-Precision Application: Welding thin-walled components, such as small motor end caps)
Core Requirements: Matching laser power and welding speed to the base metal melting point ensures uniform weld penetration. The two materials share identical melting points (approximately 1538°C) and thermal expansion coefficients (approximately 12×10⁻⁶/°C). At the same laser power (e.g., 1.5kW) and welding speed (e.g., 1.5m/min), weld penetration (e.g., 0.3-0.5mm) and build quality (no porosity or undercut) are identical, eliminating the need for process adjustments based on grade.
4. Post-weld Treatment Compatibility
If post-weld treatments such as stress relief annealing or painting are required, the two materials respond identically:
The stress relief annealing temperature (e.g., 600-650°C) and holding time are identical, resulting in no difference in residual stress relief after annealing.
The surface roughness of the weld area (consistent with the base material) does not affect paint adhesion, eliminating the issue of paint peeling easily on DC01 welds but not on SPCC welds.