Feinkornstähle HHO-02.071

Hoesch Hohenlimburg

Hot Rolled Low Pearlite Fine-Grain SteelsThe spectrum of the design success

tk

A business unit of ThyssenKrupp

Steel

Solutions from Hohenlimburg narrow strip:

performance parts for mobile thinking

Core competence of HoeschHohenlimburg is practical application dialogue.

Precisely for this reason narrowstrip from Hoesch Hohenlim-burg presents an outstandingbasis as input stock:

• in widths up to 700 mm and thicknesses from 1.5 to 16 mm

• with mill edges

• optionally split to smallerwidths or with trimmed edges

• with uniquely thickness tole-rances for hot rolled narrowband

• in best surface quality withuniform material properties

Each new vehicle generationsets new challenges. Partnersin the automobile industrytake the broad view if theirstructural components are tomeet these demands.

Microalloyed fine-grain steels -made with flexibility for the market

These days the demands of theautomobile industry and com-ponent suppliers are equally asmulti-featured as particular.Sometimes weight saving is thedecisive factor – other timesrequirements for yield and tensile strength. And that iswithout mentioning the possibi-lities for economic further pro-cessing which are always at thetop of the list with practicaldecision-making.

With their particular properties,microalloyed fine-grain steelsfrom Hoesch Hohenlimburg area basis for maximum applica-tion related suitabillty and relia-bility – with the most variedsubassemblies.

2

Feinkornstähle HHO-02.071

The following applies in parti-cular for fine-grain steels:high yield point values withoutstanding cold formability.

From practical experience andthrough stepped up customerwishes – for example in thefields of higher strengths andthinner strip gauges – HoeschHohenlimburg has expandedthe range of designations.

A set of special designationshas been developed for theapplication-oriented solution ofproblems. The in-house HSMdesignations (Hoesch SpecialSteels Microalloyed) in theirproperties and strength valuesexceed the normal productsfrom S315 MC to S 700 MC.Continuous process-automatedproduction and optimum settingof required parameters favour

Pages 6-7SubassemblySeatsOutstandingmechanical properties

Pages 4-5SubassemblyRestrainingsystemsWeight reductionthrough high tensile materials

Pages 8-9SubassemblyEngine / gearboxFirst class ductility

Pages 10-11SubassemblyAxlesOptimum thicknessranges

Pages 12-13SubassemblyBrakesTight tolerances

Pages 14-15Further processingFine blanking/weldingCustomer-serviceSelection and furtherdevelopment of materials, optimisation of production, laboratoryinvestigations

3

microalloyed fine-grain steelsfrom narrow strip precisely forthe demands of direct proces-sing: for example increase safety of passive and activerestraint systems, seat compo-nents or in drive trains.

Easily resistant to tensile forces – with lightness

Microalloyed fine-grain steels,in the high strength range,contribute to weight reductionof the end products – particu-larly important for applicationsin the automotive field.

Maximum values for ultimatestrength achieve the desiredweight reduction and go handin hand with the necessaryaspects of safety and quality.

Light and yet robust – this iswhat counts with restrainingsystem components.

Cooling line of the narrow strip mill

Belt coiling frame

Seat belt fitting

Airbag components

Subassembly: restraining systems

4

Feinkornstähle HHO-02.071

Strong restraint gives security in all situations.

Matched material qualities create the necessary prerequisites.

Fine-grain steels from HoeschHohenlimburg, together withmodern manufacturing tech-niques, make the substitution of ”heavy“ cast or forged parts possible and thus saveweight, machining processesand energy.

Thus material qualities play an important role, as well asthe fact that costs need to be”restrained“ in view of inter-national competition.

Seat belt height adjuster

5

Hoesch designation

Designation i.a.w.DIN EN 10149-2, 1995

Designation i.a.w.[Steel - Iron Material List]

Material No.:

HSM 260

HSM 300

HSM 340

-

HSM 380

HSM 420

HSM 460

HSM 500

HSM 550

HSM 600

HSM 650

HSM 700

HSM 760

1.0970*

1.0972*

1.0974

1.0976

1.0978

1.0980

1.0982

1.0984

1.0986

1.8969

1.8976

1.8974

Hoesch special product

(Q St E 260 TM*)

(Q St E 300 TM*)

Q St E 340 TM

-

Q St E 380 TM

Q St E 420 TM

Q St E 460 TM

Q St E 500 TM

Q St E 550 TM

(Q St E 600 TM*)

(Q St E 650 TM*)

(Q St E 690 TM*)

-

S 315 M

-

S 355 MC

-

S 420 MC

S 460 MC

S 500 MC

S 550 MC

S 600 MC

S 650 MC

S 700 MC

* In accordance with the Stahl-Eisen-Liste [(German) Steel - Iron List], 1990 Edition

Optimum possibilities foradjustment and solid anchoringare important safety factors.Further minimisation of riskthrough consequent design,which promotes concentrationduring driving and preventspremature fatigue thereforealways remains a complexdevelopment task. Here thechoice of material is an impor-tant design factor.

Highly developed fine-grainsteel products from HoeschHohenlimburg offer, for nume-rous applications including carseats, outstanding mechanicalproperties – overall better opti-mised than DIN EN 10149-2demands and also above theuppermost limit of this validstandard specification.

Top mechanical properties:a status above the standard

Cooling line control stand

Seat rail

Car seat - fixing device

Subassembly: seats

6

Car seat - side component

Feinkornstähle HHO-02.071

The table shows as an examplethe possible narrow spread ofthe technological parameters of the Hoesch Hohenlimburgnarrow strip.

The way one sits is the way one drives.

The input stock must also ”sit“ precisely.

7

Car seat fixture

Yield pointN/mm2 min.

HSM 300

HSM 340

HSM 380

HSM 420

HSM 460

HSM 500

HSM 550

HSM 600

HSM 650

HSM 700

HSM 760**

300

340

380

420

460

500

550

600

650

700

760

400 - 480

420 - 500

450 - 530

480 - 580

520 - 620

550 - 650

620 - 720

650 - 750

700 - 800

750 - 900

850 - 1000

27

25

23

21

19

19

17

17

17

15

15

Ultimate strengthN/mm2 from – up to

* Strip thickness > 3.0 mm

** Hoesch Special Product (up to strip thickness of 13.0 mm)

Elongation at fracture% Lo = 5do*

Hoeschdesignation

Performance impulse for ideal direct processing

It is precisely in metal formingtechnology that the inputmaterial used is of decisive significance. And that is what is delivered by Hoesch Hohen-limburg. The special advantageof microalloyed fine-grainsteels: strength in combinationwith the best prerequisites forprocessing.

Incidentally: HSM steels can be bent with tight radii, roll-formed to shape and easilyshaped.

Reversing stand

Carrier plate

Hub ring gear

Subassembly: engine/gearbox

Gearshift fork

8

Feinkornstähle HHO-02.071

Not until there is smooth interplay between engine and gearbox is power applied to the road.

All components in their turn must fulfil their function reliably –

even under continuous maximum loading.

dispensed with. The cold for-mability is improved throughthe chemical combination ofspecial alloying concepts.

With thermomechanical rollingof fine-grain steels, yield point,elongation at fracture and uni-form elongation are closelyassociated with ultimatestrength (see tables).

Fine-grain steels for cold forming

The various products are extre-mely suitable for direct proces-sing with high demands on coldformability – and can thusreplace normal heat-treatablesteels. Therefore, an expensivehot forming and/or heat treat-ment of components can be

900

200300 400 500 600 700 800 900

R (N/ 2)

Reh

(N

/mm

2 )

300

400

500

600

700

800Reh

0,8 Rm

1,0 Rm

60

50

40

30

20

10

0300 400 500 600 700 800 900

A5,

Ag

(%)

A5

Ag

Dependence of upper yield strength ReH on tensilestrength Rm

Dependence of the elongation at fracture and the uniformelongation on the ultimate strength

9

Gearbox component

Optimum dimensioning. Even for larger material thicknesses

Employed as axle or axlesuspension the material certainlyhas to put up with a lot – loadsfrom vehicle mass and dynamicforces from road interaction.

In the dialogue with customerdesign and development staffHoesch Hohenlimburg will pro-pose suitable steel grades in abroad spectrum of thickness –for maximum service life.

The coise of fine-grain steelscovers the complete range upto max. 700 mm width andmax. 16 mm thickness in coilsand cut lengths. This repre-sents an unusual range ofdimensions for microalloyedfine-grain steels in the shape of hot rolled narrow strip.

Overall view pickling plant

Subassembly: Axles

10

Rear axle

Axle end seating

Feinkornstähle HHO-02.071

Everything depends on the axle design.

An accurate layout influences the chassis-specific characteristics of a given vehicle design.

One needs to find the right measure to insure stable driving conditions.

The complete spectrum of thickness can be rolled and further processed inHohenlimburg: slitting, cuttingto length, pickling – with thickness tolerances entirely as desired over the completewidth and length.

The fine-grain crystallinestructure of HSM steel can also be achieved through thedeliberate setting of the rollingtemperatures and the degree of deformation.

Transverse control arm

Slitting line

11

”Impressive“ safety – for individual design requirements

Finishing train

All components and systems ofthe brake assembly must beable to withstand the toughloads at any second.

Microalloyed fine-grain steelsoffer quite narrow spreads oftensile values – completely inline with the design require-ments. Hoesch Hohenlimburgrestricts the relatively generousrange for yield and tensilestrength values allowed by DINEN 10149-2.

Subassembly: Brakes

12

Brake pedal

Ball pressure accumulator

Feinkornstähle HHO-02.071

Precision brake systems recognise no compromises as, in critical situations, it all depends

on correct functioning. Every bit of safety reserve counts.

And naturally material quality also belongs to this.

Due to tight dimensional tole-rances Hohenlimburg narrowstrip puts you always on thesafe side of your design – forthe safety of both the productand the ”end user“, the driver.

HSM designations set their ownstandards and offer better alter-natives over and above justmeeting standard specifications.

Impulse wheel

13

Fineblanking:

HSM steels easily meet therequirements for fineblankingthrough the fine-grain micro-structure and low pearlite con-tent.

Welding:

HSM steels can be easily wel-ded in line with all knownmethods. Welding fillers shouldbe matched to the level ofstrength and the good ductilityof the basic material. Lowercarbon and manganese as wellas microalloying contents deter-mine a low carbon equivalentand therefore guarantee goodwelding properties. With thetypes of steel up to HSM 500

Easy subsequent processing - support along the complete line

no fundamental excessive har-dening or work softeningoccurs. With the other types ofsteel one has to reckon withslight weld hardening only.They remain, however, belowthe corresponding values of S 355 engineering steel.

Information on heat treatment:

Our microalloyed fine-graindesignations, due to the ther-momechanical treatment, arefundamentally unsuitable forheat treatment. Heat treatmentabove 580 °Celsius, in particu-lar with long holding times, isassociated with a lowering ofthe yield point and ultimatestrength values.

0,3

0,25

0,2

0,15

0,1

0,05

0

CÄ

q (%

)

S 2

35

S 2

75

S 3

55

HS

M 3

00

HS

M 3

80

HS

M 4

60

HS

M 5

00

HS

M 6

00

HS

M 7

00

HS

M 7

60

General engineering steels Microalloyed fine-grain steels

14

Comparison carbon equivalentswith general engineering steels and microalloyed fine-grain steels

Feinkornstähle HHO-02.071

Diverse properties of further processing influence the total cost calculation to a high degree.

Here also there is a great deal to say for microalloyed fine-grain steels.

Individual support:we are happy to discuss yourapplications

You yourself determine at whattime and to what extent youwant to make use of our com-prehensive services. Our servi-ces cover, for example:

• advice with the selection ofmaterial

• further developments of exi-sting materials according toyour requirements

• support with your manufactu-ring optimisation

• laboratory investigations.

We can advise you already inthe planning phase on choiceof material and, together withyou, determine precisely thesuitable product. Our applica-tion engineers are often in closedialogue with customers for newdesigns and further develop-ments. They can contribute tothe optimisation of manufactureprocesses on given productionfacilities. In addition, we canalso carry out numerous testson quality assurance for you inour own laboratories.

A telephone call suffices – andour technical customer servicewill help you further.

15

A.F

.C./

08/2

003

· W

ith r

eser

vatio

n en

gine

erin

g pr

ozes

s va

riatio

n.

Hoesch Hohenlimburg GmbHNarrow Strip DivisionOeger Strasse 120D-58119 HagenTel.: ++49-23 34/91-2391 or 91-0Fax: ++49-23 34/91-3369

Technical Customer Service:Tel.: ++49-23 34/91-3245

-2271-2295

Fax: ++49-23 34/91-3358E-mail: mittelband@tks-hho.thyssenkrupp.comInternet: www.hoesch-hohenlimburg.de