Case Study: Breaking Through Strict Tolerances – Delivery Record of 200 Tons of C67 Alloy Cold Rolled Steel Strip to the European Market
In the field of high-end machinery manufacturing and precision components, the physical properties and dimensional accuracy of alloy cold-rolled steel strips directly determine the service life and reliability of the final products. Recently, Alloword successfully secured a new order of 200 tons of C67 alloy cold-rolled steel strips from a long-term European client.

This is not just a routine repeat order, but a comprehensive test of our supply chain integration capabilities, cold rolling process design, and rapid response mechanism.

I. A Demanding Inquiry: When High Precision Meets Complex Mechanical Requirements
Earlier this month, we received an urgent inquiry from a regular European customer. They required four specifications (0.30mm / 0.40mm / 0.50mm / 0.60mm x 420mm), 50 tons each, of C67 alloy cold-rolled steel strip. However, the technical specifications were extremely strict:

Extremely Narrow Dimensional Tolerance: Thickness tolerance must be strictly controlled within ±0.02mm, and the width range locked at 419-421mm.

Rigorous Mechanical Properties: Maximum tensile strength of 640 MPa, minimum elongation of 12%, and maximum hardness of 190 HV.

Extreme Forming Test: The material must pass a 180-degree bending test in both transverse and longitudinal directions without any cracking.

Pristine Surface Quality: Maximum surface roughness of 0.6 Ra, with absolutely no cracks or oxidation defects allowed.

Facing an order that demands both "high-precision dimensions" and "high plastic deformation capability," ordinary rolling mills struggle to guarantee batch stability. The transverse and longitudinal 180-degree bending requirement, in particular, poses an extreme challenge to the material's internal grain size and annealing process.

II. Same-Day Response: Process Reconstruction Based on Premium Baosteel Base Material
On the day of receiving the inquiry, our technical and commercial teams quickly collaborated, providing the client with a complete technical proposal and quotation within 8 hours.

1. Locking in Premium Base Material:
To ensure the carbon content is precisely controlled between 0.65% and 0.75%, and to eliminate bending cracks caused by inclusions at the source, we decisively selected top-tier premium steel billets from Baosteel as the base material. The high purity of Baosteel's base material is the cornerstone for achieving the subsequent complex mechanical properties.

 

2. Customized Cold Rolling and Annealing Process Design:
For the ±0.02mm thickness tolerance requirement, we utilized high-precision multi-roll cold rolling mills equipped with an AGC (Automatic Gauge Control) system for calendering.

To meet the maximum 190 HV hardness and excellent 180-degree bending performance, the technical team redesigned the spheroidizing annealing process curve. By precisely controlling the heating temperature, holding time, and cooling rate, we not only eliminated the work hardening caused by cold rolling but also achieved uniform spheroidization of carbides. This perfectly released the material's elongation (≥12%), ensuring a non-oxidized surface with roughness controlled below 0.6 Ra.

III. Details Determine Success: Export-Grade Fine Packaging and On-Time Delivery
Besides intrinsic quality, the client values packaging and delivery time equally. The coil inner diameter (ID) needed to be controlled at 400-500mm and the outer diameter (OD) at 1000-1400mm, requiring highly stable tension during the slitting and recoiling process.

To cope with the complex sea freight environment, we adopted the highest standard of export-grade fine packaging: the bottom layer is covered with anti-rust plastic film, the middle layer is wrapped with moisture-proof kraft paper, and the outer layer is fully encapsulated with iron sheets and reinforced with side guards. This ensures the 3-5 ton consolidated packages remain completely secure during container loading and unloading.

After several rounds of in-depth confirmation of technical parameters and process details, the client highly recognized our professionalism. The order was successfully finalized with net weight settlement. Currently, this batch of 200 tons of C67 cold-rolled steel strips has entered the production scheduling phase and will be shipped from Shanghai Yangshan Port on schedule at the end of March.

IV. Conclusion
From receiving the inquiry to finalizing the process, and finally securing the order, Alloword demonstrated not just trade service capability, but deep-rooted "manufacturing and engineering problem-solving capabilities" within the industry. We will continue to provide global clients with highly competitive steel supply chain solutions through rigorous processes, premium base materials, and ultimate service.

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