HC420/780DP Dual-Phase Steel: Selecting Material for Reinforcements with Stretch Transition Zones
Published
HC420/780DP is a dual-phase steel grade. For reinforcements with stretch transition zones, material selection should consider deformation in the transition, edge condition, and springback after forming. Purchasing should submit the forming process, critical transitions, allowed thinning locations, and measurement points to the supplier, and trial records must correspond to the batch and die state. Jiangsu Gaozhen handles enquiries by grade, dimensions and processing requirements.
HC420/780DP: material and applications
HC420/780DP is a dual-phase steel grade. Baosteel lists it separately from HC500/780DP; they are not the same grade. The microstructure of dual-phase steel provides a combination of ductility and strength during forming, making it suitable for reinforcements that require stretch transitions. Selection should not rely solely on the trailing number 780, because the complete grade designation indicates both yield strength and tensile strength levels. HC420/780DP and HC500/780DP have different yield requirements, and mixing them can affect springback and part dimensions. Purchasing should organize the part's forming process, critical transition zones, allowed thinning locations, and measurement points, and submit them to the supplier as input for material selection and trials. For reinforcements with stretch transition zones, the evaluation should focus on deformation in the transition, edge quality, and springback tendency. These need to be confirmed through trials in combination with die conditions and process parameters, and cannot be inferred from the grade alone.
Material-category reference: https://esales.baosteel.com/baosteel_products/automotive/products/products_03_04.jsp
Typical Parts and Processing
For an automotive reinforcement made to a drawing, section changes, local drawing and later flanging may coexist. Trial records should cover each region: measure thickness at agreed locations after drawing, inspect edges after trimming, then check dimensions after flanging and sizing.
Fix measurement locations for springback and thinning in advance so that results are comparable. Identify material batch, tooling condition and process revision on the samples. These records help locate a problem in a particular region or operation and support a focused discussion with the material supplier.
Purchasing Details and Rationale
When purchasing HC420/780DP, besides grade and dimensions, the delivery condition, surface quality requirements, and edge condition should be specified. The mechanical properties of dual-phase steel depend on processing, so the purchasing document should state the required property range and refer to the grade listing in the Gaozhen product catalog to avoid confusion with HC500/780DP. Submitting the forming process, critical transitions, allowed thinning locations, and measurement points helps the supplier assess suitability and supports later quality traceability. Trial records should correspond to the batch and die state, so that when springback or cracking occurs, it is possible to distinguish material batch variation from die or process issues. This information helps reduce trial iterations, but material suitability still needs to be verified through trials.
FAQ: Can 780 Grades Be Mixed?
No. Although HC420/780DP and HC500/780DP share the same trailing number, their yield strength levels differ. Baosteel lists them separately; they are not the same grade. The number 780 alone cannot indicate yield requirements, forming performance, or springback tendency, and mixing them may cause dimensional deviation or forming defects. Purchasing should order by the complete grade and note the batch and die state in trial records for traceability.
HC420/780DP dimensions and supply enquiry
The Gaozhen HC420/780DP product page lists these catalogue dimensions: Thickness range: 0.2-6.0 mm; Width range: 1000/1250/1500 mm. These values support specification discussions; confirm the required combination of gauge, width and condition for the material.
For this cold-rolled component, discuss cut-to-length sheets or slit coil against the developed blank. Include the final drawing and scope for cutting, CNC shearing or bending.
Product details: View related product details
Products and processing enquiries at Jiangsu Gaozhen
Jiangsu Gaozhen Trading Co., Ltd. handles trading and processing coordination for steel sheet, coil and related metal materials. Customers can find a grade and discuss drawings, service conditions and manufacturing requirements.
The product range includes cold-rolled, hot-rolled, galvanized and other coated, pickled, spring-steel, carbon-steel and stainless sheet or coil, plus zinc-titanium / zinc-copper-titanium and copper-titanium alloys. For a mixed-material project, list HC420/780DP and other grades as separate items with their own specifications.
Product catalogue: https://gaozhenmetal.com/en/products/
Enquire about HC420/780DP at Jiangsu Gaozhen
For a HC420/780DP enquiry, prepare the following information so the business team can review supply and processing against the actual component.
Material and dimensions: HC420/780DP, drawing revision or specified requirements, gauge and tolerance, width, and cut length for sheets.
Project conditions: visible faces and surface requirements, stamping or bending operations, critical corners and drawing revision.
Purchase plan: trial or batch requirement, quantity, delivery destination and requested timing.
Choose “Send enquiry” in the floating assistant, complete product, dimensions, quantity and contact details, confirm consent and submit. A receipt reference confirms that the form has been saved in Gaozhen’s website inbox. A chat message alone is not a submitted enquiry form.
Alternatively, contact Wang Dawei at +86 13861182855 or dawei5373@126.com. Mention this HC420/780DP article to help identify the product under discussion.
The business team confirms pricing, available specifications, stock and delivery against the enquiry.