|Quality||Yield point Rp0,2 |
|Tensile strength Rm |
|CR160IF||160 - 210||280 - 340||≥40||≥38||≥41||≥1,4||≥1,5||≥0,20|
|CR180IF||180 - 240||320 - 400||≥38||≥35||≥38||≥1,2||≥1,3||≥0,19|
|CR210IF||210 - 270||340 - 420||≥36||≥33||≥36||≥1,1||≥1,3||≥0,18|
|CR240IF||240 - 300||360 - 440||≥34||≥31||≥34||≥1,0||≥1,2||≥0,17|
|CR180BH||180 - 240||290 - 370||≥35||≥34||≥37||≥1,1||≥1,3||≥0,17||≥20/≥30|
|CR210BH||210 - 270||320 - 400||≥34||≥32||≥35||≥1,1||≥1,2||≥0,16||≥20/≥30|
|CR240BH||240 - 300||340 - 440||≥31||≥29||≥31||≥1,0||≥1,1||≥0,15||≥20/≥30|
|CR270BH||270 - 330||360 - 460||≥29||≥27||≥29||≥0,13||≥20/≥30|
High Strength IF and Bake Hardenable steels acc. to VDA 239-100
CR160IF, CR180IF, CR210IF and CR240IF are IF steels recommended by the German Association of the Automotive Industry (VDA). In addition to the IF steels, bake hardening steels are also part of the VDA 239-100 material specificaiton. Bake-Hardening steels includes the grades CR180BH, CR210BH-CR240BH and CR270BH.
High-strength IF steels (IF)
High-strength IF steels, like the soft IF steels, have extremely low carbon substance and are stabilized by niobium and/or titanium. As a consequence, these steels show a nearly unlimited suitability for storage. A higher solidification is achieved by adding manganese, phosphorus and/or silicon. Through the higher work-hardening, no pronounced yield point, high elongations and r-values result in an excellent formability.
Bake-Hardening steels (BH)
The higher strength of bake hardenable steels is achieved by solid solution hardening adding manganese, phosphorus and silicon. Dissolved carbon in the lattice results in a defined increase in yield strength in heat treatments, which usually occur in automotive painting processes (e.g. 170 °C, 20 minutes). This effect also improves the dent resistance for exposed outer panels. Since this shift in the mechanical properties (yield strength, elongation, n-value) is a time and temperature driven process, the suitability for storage of this steels is limited.
Nomenclature of high-strength steels according to VDA 239-100
|CR = kaltgewalzt|
HR = warmgewalzt
nnn = Rp0,2 min
|BH = Bake-Hardening|
IF = Interstitial Free
VDA 239-100 – CR210IF-UC-U
Cold-rolled Interstitial Free Steel with minimum yield strength 210 MPa, uncoated, surface quality for non-outer skin parts (internal parts).
VDA 239-100 – CR240BH-GI40 / 40-E
Cold-rolled bake-hardening steel with minimum yield strength 240 MPa hot-dip galvanized with a coating weight of at least 40 g/m² per side, surface quality for outer skin.
Further details on the possible surfaces and coatings (insert link) for the IF and BH steels according to the VDA 239-100 can be found under the respective menu item.
Roofs, hoods and door outer panels are preferred applications for BH steels. Higher strength IF steels are ideal for manufacturing complex components with high formability and strength requirements. Typical applications include wheel arches, end walls, reinforcements, tailgates, door panels, etc.
The table at the top of this page provides the first details of the high-strength IF and BH steels from the VDA material specification. You can also download the excerpt from our Quality Guides (QG) with the mechanical and chemical values for the VDA 239-100 via the previous link.
The steel grades described can be supplied as broadband or coil, slitted coils, sheets and blank.
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