In the supply chain of high-end automotive sheets and high-strength steel strips, meeting national or steel mill enterprise standards is merely the baseline. The true key to demonstrating a supplier's core competitiveness lies in their ability to address the ultimate customized demands of end-customers regarding dimensional tolerances and mechanical properties. Recently, we successfully followed up on a high-strength steel inquiry strictly adhering to Baosteel's Q/BQB419-2023 standard, formulating a customized production plan for thickness precision control. The project has now smoothly entered the quotation and negotiation stage.
I. Stringent Specifications: The Dual Challenge of Dimensions and Mechanical Properties
The material specifications requested by this client are 1.2mm × 50mm × C (Coil), with extremely demanding technical parameters:
Dimensional Tolerances: The thickness tolerance is strictly limited to +0.03mm / -0.01mm (a total fluctuation of only 0.04mm); the width tolerance is controlled within 0 / -0.15mm.
Mechanical Properties: Elongation must be greater than 11%, tensile strength must exceed 620 MPa, and yield strength must remain within a stable range of 550 MPa to 700 MPa.
II. Limitations of Conventional Mill-Finished Materials
According to standard mill-finished specifications, similar cold-rolled products are usually produced with a thickness tolerance of ±0.07mm. Faced with the client's micron-level precision requirements (+0.03/-0.01mm), the thickness variation range of conventional mill-finished materials falls far short of what is required for subsequent precision stamping or automated assembly, necessitating deep secondary refinement through advanced processing.
III. Our Diversified Customization and Production Process Guarantees
Upon receiving this client's requirements, our technical and production teams conducted a comprehensive evaluation and demonstration. Leveraging our advanced equipment advantages, we possess multiple avenues to fulfill the client's needs:
1.Primary Solution – Thickness Refinement via 20-High Precision Mill:
Relying on our advanced 20-High Sendzimir Mill and its powerful AGC (Automatic Gauge Control) system, we can apply high-precision rolling corrections to the high-strength steel strip, directly locking the thickness tolerance stably within the client's requested +0.03/-0.01mm range while ensuring that tensile strength (＞620 MPa) and yield strength metrics are perfectly met.
2.Alternative Backup Solution – "Cold Rolling + Bell Annealing" Composite Process:
If further optimization of the microstructure and elongation (required >11%) is needed after precision rolling, we can seamlessly switch to the combined production route of "precision mill reduction + bell-type annealing furnace." Through meticulous heat treatment under a high-purity hydrogen protective atmosphere, we ensure that the material achieves exceptional plasticity and elongation while retaining its high strength.
Currently, the quotation proposal for this high-standard inquiry is under active negotiation. Backed by our dual moats of "advanced equipment and specialized processes," we are committed to delivering customized special steel solutions that exceed conventional standards for global clients.
Baoshan District,
Shanghai, China.
