Quality	Standard	Material No.	Possible Surface Coating:
HCT780C	DIN EN 10338	1.0954	+ZE according to DIN EN 10152 (electrolytically galvanized)
HCT780C	DIN EN 10346	1.0954	+Z, +ZF, +ZA, +ZM (Hot-dip coating)

Testing direction	Yield point Rp0,2 (MPa)	Tensil Strength Rm (MPa)	Elongation A80 (in %)	Bake-Hardening-Index BH2
longitudinal test specimen	570 – 720	≥ 780	≥ 10	≥ 30

HCT780C is a highly developed cold-rolled complex phase steel, specified according to the DIN EN 10338 and DIN EN 10346 standards. This steel is characterized by an excellent combination of high strength and good formability, making it particularly suitable for demanding industrial applications, such as in the automotive industry. The special microstructure of HCT780C, which includes phases such as ferrite, bainite, and possibly martensite, gives it its outstanding mechanical properties.

The microstructure of HCT780C is complex and multi-layered. It mainly consists of ferrite and bainite, complemented by martensite, tempered martensite, retained austenite, and pearlite as potential additional phases. This multi-phase structure allows for high strength while maintaining excellent formability. The ferrite content ensures ductility and energy absorption, while the harder phases like bainite and martensite increase the strength and hardness of the steel. This makes HCT780C especially well-suited for applications that require both high strength and good formability.

The production of HCT780C is carried out through a precisely controlled process. Initially, the steel is hot-rolled and then subjected to controlled cooling to achieve the desired microstructure. A subsequent cold rolling process further refines the fine-grained structure and improves the steel’s mechanical properties. A final heat treatment ensures that the balance between strength and formability is optimized.

In addition to the cold-rolled variant, HCT780C is also available as a continuously hot-dip galvanized steel according to DIN EN 10346. In this process, the steel is continuously immersed in a bath of molten zinc or a zinc alloy, creating a protective zinc layer on the surface of the steel. This coating provides excellent corrosion resistance, increases the service life of the components, and improves their performance in corrosive environments. Thus, the galvanized variant of HCT780C combines the mechanical advantages of complex phase steel with enhanced corrosion resistance.

Complex phase steel, abbreviated as C, is a category of steel characterized by a multi-phase microstructure. This structure mainly consists of ferrite and bainite, supplemented by martensite, tempered martensite, retained austenite, and pearlite as potential additional phases. This multi-phase nature ensures that the steel offers both high strength and good formability. The ferrite content provides ductility and energy absorption, while the harder phases like bainite and martensite enhance strength and hardness. These properties make complex phase steel a versatile material for various industrial applications.

HCT780C is primarily used in the automotive industry, where the highest material performance standards are required. Due to its high strength and good formability, this steel is especially suitable for the production of safety-critical body parts such as reinforcements, impact absorbers, and structural components. The continuously hot-dip galvanized variant of HCT780C is ideal for applications that require both mechanical performance and high corrosion protection, such as exterior body parts and underbody components.

Compared to other complex phase steels like HCT600C, HCT780C offers higher tensile strength, making it particularly suitable for applications that require very high strength. While HCT600C offers better formability due to its lower strength, HCT780C enables higher load-bearing capacity and strength. These differences make HCT780C a suitable choice for applications where maximum strength and acceptable formability are required.

The production and application of HCT780C are carried out according to the strict requirements of the DIN EN 10338 and DIN EN 10346 standards. These standards ensure that the steel meets high quality and performance criteria. Regular tests and inspections throughout the production process guarantee that the steel’s mechanical properties and corrosion resistance are consistently maintained and that the steel is suitable for its intended applications.

In summary, HCT780C offers an excellent combination of strength, ductility, and corrosion resistance. Compliance with DIN EN 10338 and DIN EN 10346 ensures consistently high quality and performance, making it a preferred choice for modern manufacturing processes and applications.