Batch Annealed CR Steel: The Backbone of Precision Manufacturing

In the realm of highprecision metal forming, Batch Annealed Cold Rolled (BA CR) steel stands as a cornerstone material. Manufactured by Tianjinbased Runfei under globally recognized certifications including ISO 9001, SGS, and RoHS Directive compliance, this engineered steel delivers unmatched consistency for industries demanding rigorous dimensional accuracy and surface integrity. Unlike conventional coldrolled products, BA CR undergoes a specialized thermal treatment process that fundamentally optimizes its microstructure – a critical advantage for punching, deepdrawing, and coating applications.  

Defining the Technology: What is Batch Annealing?  

Batch annealing is a controlled metallurgical process where multiple coldrolled steel coils are stacked within a sealed furnace chamber. Subjected to a precisely managed heating cycle (typically 680°C–720°C) in a protective hydrogennitrogen atmosphere, the steel is held at peak temperature for 24–48 hours followed by gradual cooling. This deliberate thermal rhythm accomplishes three core transformations:  

1. Recrystallization: Erases workhardening effects from prior cold rolling, restoring ductility.  

2. Stress Relief: Eliminates internal tensions that cause warping or springback.  

3. Grain Refinement: Creates uniform ferrite crystals for isotropic mechanical properties.  

Runfei’s BA CR adheres to AISI, ASTM, BS, DIN, GB, and JIS standards, guaranteeing seamless integration into global supply chains from automotive OEMs to electronic component suppliers.  

Tangible Advantages for Industrial Users  

The batch annealing difference manifests in measurable performance gains:  

 Enhanced Formability: Grades like SPCC and SGCC achieve elongation rates of 32–42%, enabling complex geometries in stamping (e.g., automotive fuel tanks, electrical cabinet hinges) without fracture. The material’s plastic strain ratio (rvalue) exceeds 1.8, a key indicator for deepdrawing stability.  

 Premium Surface Readiness: Postannealing surface roughness (Ra) measures ≤0.5μm – virtually free of oil residue, scratches, or scale. This pristine base minimizes pretreatment costs for painting, galvanizing, or powder coating.  

 Certified Safety Compliance: As RoHS Directivecompliant material, Runfei’s BA CR contains no lead, cadmium, or other restricted substances, making it ideal for consumer appliances, food packaging equipment, and medical device housings.  

Precision Specifications: Runfei BA CR in Detail  

Runfei produces BA CR coils with thicknesses spanning 0.20 millimeters to 2.0 millimeters, catering to applications from ultrathin electronic shielding (0.2–0.5mm) to structural brackets (1.5–2.0mm). Standard widths range from 914mm to 1500mm, optimized for slitting or direct feeding into stamping lines. Available grades include commercial steels Q235/Q235B and coldrolled specific SPCC/SGCC, balancing strength (Q235B tensile: 375–500 MPa) with formability (SPCC elongation: ≥34%). Coils feature 508mm or 610mm inner diameters with weights per coil standardized at 3 to 8 metric tons. Every shipment undergoes waterproof plastic wrapping and steel belt reinforcement, ensuring ocean freight durability in horizontal or vertical configurations.  

From Furnace to Factory: The Manufacturing Journey  

Runfei’s production protocol begins with severe cold reduction (50–90% thickness compression), aligning the steel’s grain structure. Next, the batch annealing phase in gastight furnaces initiates recrystallization. Finally, a critical skinpass rolling step imposes 0.5–1.5% elongation, locking in dimensional flatness (±1.5 Iunits) and enhancing surface texture. This triad of processes yields steel with mechanical properties that remain homogeneous across coil lengths – a nonnegotiable requirement for highspeed stamping.  

IndustrySpecific Applications: Where BA CR Excels  

 Automotive Engineering: Leveraging thicknesses of 1.0–2.0mm (Grade Q235B), BA CR forms seat adjusters, brake pedal supports, and structural reinforcements, where consistent bendability and weldability are paramount.  

 Home Appliance Manufacturing: Refrigerator inner liners (0.6–0.8mm SGCC) and washing machine balance rings (1.0–1.2mm SPCC) rely on BA CR’s flawless surface for porcelain enameling or PVC lamination.  

 Electronics & Telecommunications: Server rack mountings (0.8–1.0mm Q235) and lithiumion battery casings (0.3–0.5mm SPCC) utilize its electromagnetic shielding properties and RoHS compliance.  

 Building Systems: Suspended ceiling grids (0.4–0.7mm) and HVAC ducting (0.9–1.5mm Q235) benefit from its corrosionresistant base for postpainting longevity.  

Operational Assurance with Runfei  

1. Capacity Guarantee: Our Tianjin base boasts a monthly production capacity of 21,000 metric tons, enabling continuous delivery of orders exceeding 10,000 tons.

2. Compliance Backed: RoHS Hazardous Substance Testing Report + SGS Material Verification + ISO 9001 Process Traceability.

3. Trade Assurance: Alibaba Trade Assurance protects your payment, product quality, and ontime delivery.

4. Geographical Advantage: Our strategic location at the Tianjin Port export hub shortens shipping times to Japan, South Korea, and Southeast Asia.

Conclusion  

Batch Annealed CR is not merely a commodity steel – it’s a processvalidated solution for manufacturers pushing the limits of metal forming efficiency. Runfei’s mastery of annealing kinetics, paired with Tianjin’s logistical advantages, positions this BA CR as a strategic material choice for exportfocused production.