Cost Reduction and Light Weighting (BIW)

ENGINEERING
TITLE: LIGHTWEIGHTING (Vehicle Design and Development)

farshidhesami@gmail.com
Cost reduction and Light weighting

(BIW)
https://www.linkedin.com/in/farshid-hesami-33a09529/
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ENGINEERING
Applications for hot stamped LWBs
A key advantage of hot stamped LWBs is that several applications can be combined and
stamped as a single part. As well as reducing costs and material use, these complex parts
can lead to additional weight savings and even better safety performance.
Hot stamping also improves the geometric accuracy of parts – an important
consideration during vehicle assembly.
What is a laser welded blank?

LWBs combine two or more steel blanks into a single laser welded blank. PHS LWBs
are then hot stamped to form the part.
The technology ensures the right steel, in the right thickness, is in the right place for
safety and performance. The crash behavior of LWB parts can be finely tailored to
ensure maximum weight savings while enhancing safety.
When advanced high strength steels, such as PHS grades, are used to form an LWB, the
part can be significantly lightened. This ensures lower fuel consumption and emissions
during use and minimizes the amount of steel required.
The use of PHS LWBs in modern vehicles began to grow rapidly from 2009, largely in
response to global emissions regulations. Partially ablated LWBs were used to
manufacture the first single-piece hot stamped door ring made entirely from PHS. The
solution was first deployed on Acura MDX, and led to weight savings of 20 percent
compared to a conventional door assembly.
The Honda Acura MDX went on to win numerous car industry awards which recognize
the pioneering manufacturing process and safety improvements of this steel solution.
The single-piece hot stamped door ring has now been adopted by many OEMs including
Chrysler and Dodge.
The door-ring concept has been adapted to include a laser-welded inner and outer front
door ring system. The first production vehicle to use the new inner and outer door ring
blanks will be the Honda Acura RDX.
This latest development has been shortlisted for the 2019 PACE Awards.The outer door
ring – a key part of the body structure which gives the vehicle its strength and stiffness –
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ENGINEERING
replaced conventional multi-piece, spot-weld designs. The technology was implemented

in additional Honda vehicles including the Pilot and Odyssey.
“The outer and inner door ring system takes our safety protection to the next level. The
solution manages loads coming from the front of the vehicle and translates them through
to the back of the structure.
It also balances side type of crash modes to prevent intrusion into the cabin and protect
the occupants from all directions," said Riggsby. "This vehicle also features a panoramic
sunroof, and with two door rings, it really performs well."
Aluminum-silicon (AlSi) coating

The aluminum silicon (AlSi) is a unique coating which is used on ArcelorMittal’s steels
for hot stamping. This allows OEMs to use a simplified hot stamping process:
 Scale and surface decarburization are eliminated without the need for protection
gas.
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ENGINEERING
 The final product exhibits excellent corrosion protection properties.

ArcelorMittal has developed a patented process called laser ablation which removes this
coating for laser welding, without affecting the strength or corrosion resistance of the
part.
Hot stamped LWBs have been adopted by most major carmakers since they were first
introduced in the 1990s. Today carmakers are increasingly deploying them in
production vehicles to achieve their ambitious weight reduction and safety targets.
New hot stamping grades such as Usibor® 2000 and Ductibor® 1000 are pushing the
boundaries of what can be achieved with advanced LWBs. They are particularly useful
in safety-critical structural components of the body-in-white (BIW) and provide an
excellent balance between strength and formability.
They can optimize BIW components in terms of:
 Anti-intrusion
 Energy absorption
 Load transfer properties
Single-piece door ring enhances safety

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ENGINEERING
ArcelorMittal’s world-leading automotive Global R&D team have developed a single-

piece door ring using LWBs. The simplified door ring replaces four separate parts. As
well as optimizing weight and reducing costs, the solution enhances crash performance
significantly and can lead to weight savings of up to 20 percent.
The door ring concept has already been deployed in production vehicles on the road in
various regions today and is winning awards for its innovative contribution to safety and
reducing weight.
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ENGINEERING
Cost-effective weight reduction
The added value of these S-in motion® Mid-Size Sedan and SUV design solutions:
 Achieving a from 20% to 26% body structure weight reduction compared to

representative 2015 North American vehicles
 Helping OEMs achieve cost-effective weight reduction to meet stringent fuel
economy standards in a multi-vehicle platform
 Maintaining or improving safety performance
These solutions utilize new advanced steel products and solutions, including products
that are available now or in the near future:
 Hot stamping steels: Usibor® 1500 and 2000 - Ductibor® 500 and 1000
 Cold stamping steels: Fortiform® 980 and 1180, Dual Phase 490 exposed
 Martensitic steels: MartINsite® 1200, 1500 and 2000
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ENGINEERING
Partial ablation technology:
Partial ablation technology was developed to ensure that hot stamped laser welded
blanks (LWBs), made from the latest press hardenable steels (PHS), are as safe as
possible. Although it was first used industrially in 2007, the patented partial ablation
process is proving more popular than ever with carmakers. It is now used by numerous
carmakers and has led to dramatic improvements in lightweighting and safety.
By 2020, ArcelorMittal expects the technology will have been used to produce more
than 70 million PHS LWBs using ablation technology at locations around the world.
PHS are typically supplied with an aluminum-silicon (AlSi) coating which protects the
underlying steel during thermal treatments and prevents corrosion. ArcelorMittal’s
patented partial ablation process removes a thin strip of the AlSi coating on the edge of
the blanks before they are laser-welded together. If the coating is not removed before
laser welding, the aluminum it contains can weaken the weld and cause the part to fail.
Around 99 percent of the PHS LWBs made today utilize AlSi coated steels.
Welding of hot stamped LWBs:
The aluminum-silicon coating on steels for hot stamping must be removed before
welding. Company has patented a process known as laser partial ablation to efficiently
weld hot stamping steels such as Usibor® and Ductibor®.
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ENGINEERING
The process partly removes the aluminum-silicon coating before the welding operation,
ensures high weld quality, and maintains corrosion resistance around the welded area.
 The top layer is removed to avoid excessive Al dilution in the weld.

 The intermetallic layer is intentionally kept to guarantee corrosion protection.
This process allows uniform hardness distribution after hot stamping, guaranteeing the
weld quality.
Using patented ablation technology, a laser beam is used to remove the aluminum-
silicon (AlSi) layer on the top of the press hardenable steel (PHS).
The intermetallic layer is preserved during the operation to ensure corrosion resistance.
After ablation, two or more blanks are welded together to form a single PHS laser
welded blank (LWB). PHS LWBs are then hot stamped to form the part.
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ENGINEERING
Removes the AlSi coating while preserving the intermetallic layers which sits between
the coating and the underlying steel.
New advanced steels lightweight critical chassis components

One of the most important structures in a vehicle is the chassis system. Forming the
under-structure of a vehicle, the chassis includes of a series of fundamental components
which manage vehicle dynamics, comfort, suspension, and steering.
Chassis parts are also critically important to passenger safety, particularly when
unexpected events occur while the car is in motion. An S-in motion® study from
company shows how OEMs can maintain the safety of the chassis while achieving
significant weight savings with advanced high strength steels.
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ENGINEERING
S-in motion® Chassis study covered both pickup trucks and passenger vehicles
Specific requirements for chassis parts

Chassis parts must provide adequate stiffness for the vehicle while resisting cyclic,
incidental, and accidental loads.
They also need to resist the effects of aggressive corrosion environments as they are
located close to the road. In order to meet these highly specific criteria, Company has
developed AHSS for cold stamping with specific properties including excellent forming
and fatigue properties.
During the development of these grades, the properties of the steels were optimized to
facilitate the manufacturing of chassis components. The modifications enhanced cut
edge formability and the hole expansion properties of the steels, allowing OEMs to
design chassis parts with flanged edges and stretched holes.
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ENGINEERING
New cold stamping grades for chassis applications

One of the grades has developed for chassis applications is FB590HHE (HHE stands for
High Hole Expansion). This exceptional hot rolled ferrite-bainite steel offers excellent
hole expansion. The grade allows OEMs to optimize the formability and manufacturing
of cold stamped parts with flanged holes and stretched edges such as lower control
arms.
The most promising grade for significant weight reduction is CP800SF, a hot rolled
steel suitable for stretch forming (SF). This grade was developed with an ultimate
tensile strength (UTS) of 800 MPa. Hardening is achieved through a micro-alloyed
complex phase microstructure.
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ENGINEERING
The ultimate AHSS for chassis applications is the cold rolled grade CP1000SF (Stretch
Flange able).
The steel has a UTS of 1000 MPa while offering excellent stretch flange ability. In the
S-in motion® Chassis study, the grade was used in combination with hot rolled
CP800SF to achieve weight reductions of 15 percent on the engine cradle.
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ENGINEERING
The use of CP800SF and CP1000SF enabled the weight of the engine cradle to be
reduced by 15 percent
Advantages of laser welded blanks

Laser welded blanks (LWBs) enable carmakers to reduce the weight of a monolithic
part. At the same time, the strength or safety performance of the part can be maintained
or improved, depending on the combination of steels selected.
Key advantages of LWBs include:
 Material optimization
 Improved technical performance without increasing weight
 Simplification of the OEM’s production processes
 Weight and thickness reductions for the complete assembly
 Butt-joining to avoid overlaps
 Safety improvements
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ENGINEERING
Material optimization
During the blanking step, laser welded blank shapes can be arranged to make maximum
use of the steel. Known as ‘nesting’, this technique increases the number of parts that
can be made from one sheet of material. Less steel is required, and less scrap is
produced.
The right steel grade is in the right place, in the right thickness to create a tailor-made
solution for each part.
Depending on the shape, scrap rates can be as low as seven percent. With lower scrap
rates, cost efficiency is increased significantly.
Nesting can lead to significant material savings depending on the shape of the parts to
be blanked.
More than one-third of the coil can be scrapped if monolithic blanks are utilized
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ENGINEERING
Improved technical performance without increasing weight

Using LWBs, the technical performance of a part can be enhanced significantly without
adding to the weight of the vehicle.
Examples of improved technical characteristics include:
 Higher stiffness
 Better energy absorption
 Improved crash behavior
Simplification of the OEM's production processes

OEMs can simplify their production processes with LWBs thanks to:
 Reduced number of parts
 Improved crash behavior
 Reduction in the number of stamping and assembly tools required
Weight and thickness reductions for the complete assembly

LWBs are a clever way to significantly reduce the mass of a part or the body-in-white of
a vehicle. Thanks to the very high strength of modern automotive steels, very thin
gauges can be utilized. Using some of the most advanced high strength steels, weight
savings of 10 to 20 percent (or more) can be achieved for a single part.
The weight savings occur because:
 The thickness of the steel used in a LWB part can be optimized to eliminate
unnecessary weight.
 The steel blanks are butt joined. Overlaps are reduced to a minimum, cutting
weight significantly.
By ensuring the right material is in the right place, in the right thickness, LWBs can
significantly reduce the weight of a part.
The following image shows the example of a door ring. The LWB solution on the right
can be up to 20 percent lighter than the multi-part door assembly shown on the left.
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ENGINEERING
Safety improvements
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ENGINEERING
Optimized laser welded blank shotgun solution with several Dual Phase steel grades leads to best compromise to cope with
all frontal crash tests
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ENGINEERING
S-in motion® Mid-size SUV achievements
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ENGINEERING
Achievements for mid-size sedan:
 Weight reduction of 86 kg (23%) with currently available steel grades

 14 kg (26% total) extra weight reduction with emerging grades
Achievements for mid-size SUV:
 Weight reduction of 102 kg (20%) with currently available steel grades

 10 kg (21% total) extra weight reduction with emerging grades
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ENGINEERING
Weight reductions-in motion® for pickup trucks

Created two S-in motion® sets of solutions for pickup trucks to reduce average weight.
Both have been refined and extended to help meet the specific challenges facing the
North American light truck market.
S-in motion® solutions for pickup trucks meet OEMs’ acceptance criteria and have
been validated for all major automotive standards, including crash safety and stiffness
requirements.
Solution 1 can be implemented now

The first solution uses advanced high strength steels and press-hardened steel grades
which are already available. These include grades such as Usibor® 1500 and
Ductibor® 500. Deploying available solutions can already reduce weight by up to 174
kg (384 lbs) compared to a 2014 baseline vehicle. That equates to a saving of 23% on
the combined weight of a pickup’s cab, box, frame and closures.
Reducing average pickup weight by 174 kg saves more than 14 grams of CO2-
equivalent emissions per kilometer. It ensures pickup trucks meet existing regulatory
standards in both the EU and US.
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ENGINEERING
Weight Weight saving vs Weight saving vs

(kg) baseline (kg) baseline
Cab 211.4 81 28%
Front doors 41.5 4 8%
Rear doors 33.2 5 13%
Box 84.9 24 22%
Tailgate 14.7 5 25%
Upper body total 385.7 119 23%
Frame 188.2 55 23%
Under body total 188.2 55 23%
Total Scope 574 174 23%
Solution 2 for advanced emission targets

Emissions reduction regulations in the EU and US are driving auto manufacturers to
develop lighter, more fuel efficient vehicles. In the EU, OEMs have to lower average
emissions to 95g of CO2 per kilometre by 2020. In the US, the target is 54.5
miles/gallon by 2025.
ArcelorMittal’s second S-in motion® set of solutions for pickup trucks uses emerging
grades in the final stages of development which can meet these advanced targets.
ArcelorMittal has calculated that these grades will reduce pickup weight by an
additional 22 kg.
The innovative new steel solutions include advanced steel grades developed by
ArcelorMittal’s R&D teams in Maizières-lès-Metz and Montataire (France) and East
Chicago (US).
These solutions provide further evidence that steel is the most sustainable, versatile and
affordable material to help automotive manufacturers achieve weight reduction targets
on time - without compromising strength and safety.
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ENGINEERING
Highlight
 174 kg (23%) of weight savings compared to baseline weight (748 kg)
 Optimal solution embarks 63% Advanced High Strength Steels including 18% Press Hardened
Steels
 Solutions are validated for crash and stiffness requirements
 Main complex parts are validated for forming and assembly
Impact strength (Steels for cold stamping)

As a result of their very high yield and breaking strength, Fortiform® 1050 steel is particularly suitable for
safety parts.
Fortiform® steels have been characterized in a 3-point bending test using top hat cross-section test-pieces
impacted at 30 kph. The tests showed excellent behavior by these steels. By way of information, the graph
below shows the minimum weight-saving potential with these steels relative to a CR340LA steel.
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ENGINEERING
Safe and affordable steel solutions for the battery pack of BEVs
The battery pack is one of the most vital parts of a BEV as it houses the battery cells - the most expensive
component of a vehicle. As well as protecting the cells and their associated equipment from external
elements, the battery pack must keep the vehicle and its passengers safe from battery, fumes, fire, and
electromagnetic fields.
The BEV S-in motion® study found that ArcelorMittal products such as MartINsite® (for roll
forming) offer best-in-class protection and performance for the battery pack.
As BEVs are more expensive to produce, mainly due to battery costs, AHSS like these remain the optimal
solution to reach the OEM’s cost, performance, and environmental targets. The battery pack
solutions prove that light weighting, safety and fire protection can be combined – and at the same time
allow high cost savings as well as lower carbon emissions over the entire life cycle.
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ENGINEERING
Exploded view of ArcelorMittal's main S-in motion concept for battery pack
structure
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ENGINEERING
LIGHTWEIGHTING
 TODAY’S USAGE OF STRUCTURAL BODY ADHESIVES
Today most car bodies contain structural or crash toughened adhesives, with bond lengths ranging from 30
to 200 meters and more. This corresponds to a weight of 0.2 kg (30 m) and 1.5 kg (200 m).
MAIN ADVANTAGES OF USING ADHESIVE BONDS IN BIW:

 Improving structural performance
 Saving weight
 Improving corrosion protection
 Isolation against galvanic corrosion in mixed-material joints

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ENGINEERING

TITLE: LIGHTWEIGHTING (Vehicle Design and Development)

Cost reduction and Light weighting

Applications for hot stamped LWBs

What is a laser welded blank?

replaced conventional multi-piece, spot-weld designs. The technology was implemented

Aluminum-silicon (AlSi) coating

 The final product exhibits excellent corrosion protection properties.

Single-piece door ring enhances safety

ArcelorMittal’s world-leading automotive Global R&D team have developed a single-

Cost-effective weight reduction

 Achieving a from 20% to 26% body structure weight reduction compared to

Partial ablation technology:

Welding of hot stamped LWBs:

 The top layer is removed to avoid excessive Al dilution in the weld.

New advanced steels lightweight critical chassis components

Specific requirements for chassis parts

New cold stamping grades for chassis applications

Advantages of laser welded blanks

Key advantages of LWBs include:

Improved technical performance without increasing weight

Simplification of the OEM's production processes

Weight and thickness reductions for the complete assembly

S-in motion® Mid-size SUV achievements

Achievements for mid-size sedan:

 Weight reduction of 86 kg (23%) with currently available steel grades

Achievements for mid-size SUV:

 Weight reduction of 102 kg (20%) with currently available steel grades

Weight reductions-in motion® for pickup trucks

Solution 1 can be implemented now

Weight Weight saving vs Weight saving vs

Solution 2 for advanced emission targets

Impact strength (Steels for cold stamping)

MAIN ADVANTAGES OF USING ADHESIVE BONDS IN BIW:

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