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Choosing the right steel for your metalworking applications
Patricia Miller, Senior Technical Manager,
©2015 Bohler-Uddeholm
Selecting the Right Tool Steel for
Your Metalforming Application.
Patricia Miller,
Senior Technical Manager
Choosing the right steel for your metalworking applications
Patricia Miller, Senior Technical Manager,
©2015 Bohler-Uddeholm
Application
Work materials
Failure mechanism of tooling steel
Production method of the tooling steel
Serial length
Complexity of geometry
What parameters drive your tooling material choice?
2
Choosing the right steel for your metalworking applications
Patricia Miller, Senior Technical Manager,
©2015 Bohler-Uddeholm
Application
Work materials
Failure mechanism of tooling steel
Production method of the tooling steel
Serial length
Complexity of geometry
What parameters drive your tooling material choice?
Choosing the right steel for your metalworking applications
Patricia Miller, Senior Technical Manager,
©2015 Bohler-Uddeholm
Cold Work Applications
3
Choosing the right steel for your metalworking applications
Patricia Miller, Senior Technical Manager,
©2015 Bohler-Uddeholm
Overview of Today’s
Working Materials
Choosing the right steel for your metalworking applications
Patricia Miller, Senior Technical Manager,
©2015 Bohler-Uddeholm
Grades with good ductility Copper and copper derivatives
Aluminum
Mild steel
Stainless steel
Grades with less ductility
Cold rolled steels
Spring steels
Hard materials
Grades with higher abrasive nature
Electrical steels
Ceramics
Hard metals
Common Work Materials
4
Choosing the right steel for your metalworking applications
Patricia Miller, Senior Technical Manager,
©2015 Bohler-Uddeholm
Work Material Comparisons: Cold Forming and Stamping
0
10
20
30
40
50
60
200 400 600 800 1000 1200 1400
Form
abili
ty, A
80
(%)
Mild Steel
HSLA
DP-steel
Trip-steel
Mart. steel
Bake Hardenable
IF
MPa
58 87 116 145 174 203 KSI 29
~125HB ~180HB ~22HRC ~33HRC ~38HRC ~44HRC
70
Boron - steel
High Strength
Stainless Steel
Choosing the right steel for your metalworking applications
Patricia Miller, Senior Technical Manager,
©2015 Bohler-Uddeholm
30% martensite
70% ferrite
50% martensite
50% ferrite
100% martensite
Du
400 600 800 1000 1200 1400 Strength MPa
Dual Phase Alloys
5
Choosing the right steel for your metalworking applications
Patricia Miller, Senior Technical Manager,
©2015 Bohler-Uddeholm
Third Generation Developments: Sheet Metal Grades
Choosing the right steel for your metalworking applications
Patricia Miller, Senior Technical Manager,
©2015 Bohler-Uddeholm
M 1400 MPa
800 MPa
500 MPa
280 MPa
Shock wave during breakthrough
High force
Punch diameter: Ø 4.80 mm (0.19”)
Die clearance: 10%
Sheet thickness: 1 mm (0.039”)
Influence of Sheet Material Strength
6
Choosing the right steel for your metalworking applications
Patricia Miller, Senior Technical Manager,
©2015 Bohler-Uddeholm
Introduction to
Tooling Failure Types
Choosing the right steel for your metalworking applications
Patricia Miller, Senior Technical Manager,
©2015 Bohler-Uddeholm
Tool Steel Failure Mechanisms
7
Choosing the right steel for your metalworking applications
Patricia Miller, Senior Technical Manager,
©2015 Bohler-Uddeholm
Wear (abrasive or adhesive)
Results in a material loss and is related to the sheet material type,
the application and the process conditions
Abrasive Wear Adhesive Wear
Failure Mechanisms in Cold Work
Choosing the right steel for your metalworking applications
Patricia Miller, Senior Technical Manager,
©2015 Bohler-Uddeholm
Material is lost because of friction between tooling and work material
This is a predictable failure
Solutions for Abrasive Wear
Abrasive wear resistance is normally base on hardness and / or carbide volume of the tooling material
Tooling material
Surface Treatments
Abrasive Wear
8
Choosing the right steel for your metalworking applications
Patricia Miller, Senior Technical Manager,
©2015 Bohler-Uddeholm
Volume fraction and type of primary alloy carbide
in the heat treated microstructure:
Distribution of primary carbides
Size of primary carbides (severe abrasion only)
Hardness , quality and type of heat treatment
Chromium carbide (M7C3) 66-68 HRC
Molybdenum carbide (M6C) 72-74 HRC
Tungsten carbide (M6C) 72-74 HRC
Vanadium carbide (MC) 82-84 HRC
Wear Resistance is a function of…
Choosing the right steel for your metalworking applications
Patricia Miller, Senior Technical Manager,
©2015 Bohler-Uddeholm
Normally referred to as micro-welding of tooling material to work material.
Tooling material is pulled out.
Is often misdiagnosed as abrasive wear.
Solutions to Adhesive Wear:
Tooling material, improving chipping resistance.
Pull-out
Adhesive Wear
9
Choosing the right steel for your metalworking applications
Patricia Miller, Senior Technical Manager,
©2015 Bohler-Uddeholm
Is related to the stresses in the process and the fatigue resistance of
the tool material.
Chipping
D2
Uddeholm Vanadis® 4 Extra
SuperClean
Chipping
Choosing the right steel for your metalworking applications
Patricia Miller, Senior Technical Manager,
©2015 Bohler-Uddeholm
Occurs if the process stresses are higher than the compressive
strength of the tool steel.
Plastic Deformation
10
Choosing the right steel for your metalworking applications
Patricia Miller, Senior Technical Manager,
©2015 Bohler-Uddeholm
Occurs when the process stresses, and presence of an existing crack
result in a stress level higher than the toughness of the tooling
material.
Cracking
Choosing the right steel for your metalworking applications
Patricia Miller, Senior Technical Manager,
©2015 Bohler-Uddeholm
Is a physical and/or chemical adhesion of the work material to the tool surface.
The severity of galling depends on the surface finish and chemical composition of the tool steel and work material.
Proper use of surface treatments can also reduce galling.
Galling
11
Choosing the right steel for your metalworking applications
Patricia Miller, Senior Technical Manager,
©2015 Bohler-Uddeholm
Identify the dominating failure mechanism.
Select a tool steel with better resistance to the
dominating failure mechanism.
Goal: Reliable and economical production:
The choice will depend on the steel’s inherent
capabilities and its production method.
Method for Steel Selection in Cold Work Applications
Choosing the right steel for your metalworking applications
Patricia Miller, Senior Technical Manager,
©2015 Bohler-Uddeholm
Today’s Tool Steel Options
12
Choosing the right steel for your metalworking applications
Patricia Miller, Senior Technical Manager,
©2015 Bohler-Uddeholm
Heat Treatment Machining
ESR Re-Melting EAF Vacuum-De-Gassing Ladle Furnace Uphill Casting
Melting Shop
Stock Forging Plant Rolling Mill
Inspection &
Testing Customer
Conventional / Ingot Steel Production
Choosing the right steel for your metalworking applications
Patricia Miller, Senior Technical Manager,
©2015 Bohler-Uddeholm
High Reduction Forging
Breakdown of the solidification structure to
obtain a fine-grained austenite and freedom from
carbide networks.
Tool Steel Production: Hot Working
13
Choosing the right steel for your metalworking applications
Patricia Miller, Senior Technical Manager,
©2015 Bohler-Uddeholm
D2 Structures: Can be very different from each manufacturer
Choosing the right steel for your metalworking applications
Patricia Miller, Senior Technical Manager,
©2015 Bohler-Uddeholm
Punch made from standard D2 – premature failure
Starting material: bar rd. 33 mm
Tool Failure: D2
14
Choosing the right steel for your metalworking applications
Patricia Miller, Senior Technical Manager,
©2015 Bohler-Uddeholm
Controlled Carbide distribution with Bohler K110
Bar rd. 33 mm, Direction: Longitudinal / Magnification: x 100
Standard Grade 1.2379
Carbide Distribution
Choosing the right steel for your metalworking applications
Patricia Miller, Senior Technical Manager,
©2015 Bohler-Uddeholm
The most popular tool steels for blanking; trim, forming
and calibration dies:
AISI A2: 5 % Chromium steel, air hardening, general
purpose, hardness is 58-62 HRC.
AISI D2: 12 % Chromium steel, air hardening, high wear
resistance, hardness of 60-62 HRC.
These grades are not always suitable for demanding
coldwork applications.
Not easy to salvage when chipping, wear, or galling take
place.
The cold work tooling environment: Conventional Grades
15
Choosing the right steel for your metalworking applications
Patricia Miller, Senior Technical Manager,
©2015 Bohler-Uddeholm
The Goal: Extend the life of the tool first by minimizing failure
modes like chipping so that we can address the wear failure modes.
Time for crack initiation
Time for crack
propagation
Tool lifetime
Tool with poor
surface finish
Tool with
EDM-surface layer
Tool material with
carbide stringers
Choosing the right steel for your metalworking applications
Patricia Miller, Senior Technical Manager,
©2015 Bohler-Uddeholm
Electroslag remelting
The small amount of liquid metal solidifies much faster than a large steel melt which gives:
Less time for carbide growth during solidification.
improved homogeneity and smaller carbides.
The remelting takes place under a liquid active slag layer which removes inclusions.
Consumable
Water Cooled Mold
Molten Slag
ESR’ed Ingot
Remelting under protected
atmosphere
Conventional Tool Steel Production with Secondary Melting
16
Choosing the right steel for your metalworking applications
Patricia Miller, Senior Technical Manager,
©2015 Bohler-Uddeholm
More consistent structure in the steel
More consistent to machine.
Easier and more consistent to heat treat.
Much higher toughness and more uniform in all directions.
Permits new grade development
Allows for high temperature tempered grades to replace older
versions.
Better stability in operation.
Easier to coat.
Greater versatility in the types of coatings to use.
More uniform wear rates, with less chipping.
Benefits of Re-Melted Steel
Choosing the right steel for your metalworking applications
Patricia Miller, Senior Technical Manager,
©2015 Bohler-Uddeholm
Conventional Produced and Remelted
Bohler W360 Isobloc®:
An ESR produced very high toughness hot work tool steel, high temperature tempered to 54-56 HRC.
Uddeholm Caldie®: An ESR produced high toughness medium wear resistance tool steel. With a typical working hardness of 58-62HRC and high temperature tempering.
Readily weldable and coatable.
Bohler K340 Ecostar®/Isodur®: A medium toughness good wear resistance tool steel. With a typical working hardness of 58-64HRC and high temperature tempering. Use instead of M2, M4, D2.
Quick overview of BU Tooling Materials for High Strength Work Materials
17
Choosing the right steel for your metalworking applications
Patricia Miller, Senior Technical Manager,
©2015 Bohler-Uddeholm
8 Trim dies in Caldie
PVD TiCN coated
DP 600 sheet;
1.8 mm (0.071”) thick
Production since 2005:
800,000 parts/die with no downtime.
In total, over 2.5 millions parts have
been produced.
Results from Production Tools
Choosing the right steel for your metalworking applications
Patricia Miller, Senior Technical Manager,
©2015 Bohler-Uddeholm
Photo Micrographs are at 500x
AISI D2 8% Cr Steel ESR
Microstructure Comparison
18
Choosing the right steel for your metalworking applications
Patricia Miller, Senior Technical Manager,
©2015 Bohler-Uddeholm
8 T heat size
Large Tundish with
ESH and EMS
Fine powder
gas atomization Direct capsule filling without
extra powder handling
Cold Load
Hot Unload
HIP
Powder Metallurgical (PM) Steel Production
PM PRODUCTION ROUTE
Choosing the right steel for your metalworking applications
Patricia Miller, Senior Technical Manager,
©2015 Bohler-Uddeholm
Advantages to Tool Users
Wider selection of grades that can have better wear characteristics.
Less variation in performance.
Reduced risk of cracking and chipping failures.
Reduced risk of fatigue failures.
Longer tool life
Less Downtime and Maintenance = Improved Profitability
Powder Metallurgical Steel Advantages
19
Choosing the right steel for your metalworking applications
Patricia Miller, Senior Technical Manager,
©2015 Bohler-Uddeholm
More uniform response during tool making with regards to:
More consistent machinability/grindability.
Reduced risk of problems during EDM.
Reduced risk of problems during polishing.
Improved adherence of surface coatings.
Powder Metallurgical Steel Advantages
Advantages to Tool Makers
Choosing the right steel for your metalworking applications
Patricia Miller, Senior Technical Manager,
©2015 Bohler-Uddeholm
PM 4V Conventional Steel (AISI D2)
Improvements in Cleanliness Bohler-Uddeholm
PM Standard Market PM
Powder Metallurgical Production Process
20
Choosing the right steel for your metalworking applications
Patricia Miller, Senior Technical Manager,
©2015 Bohler-Uddeholm
Surface polished to Ra 0.029 µm
Dense distribution of very low
friction* nitro-carbides (M(N,C) to
support the work material.
Many deep lubricant reservoirs.
* Much lower friction coefficient than the carbides in our other PM steels.
New PM Technology: PM + Nitrogenated Powders
Choosing the right steel for your metalworking applications
Patricia Miller, Senior Technical Manager,
©2015 Bohler-Uddeholm
Powder Metallurgy with Uddeholm SuperClean Technology
Uddeholm Vanadis® 4 Extra SuperClean:
High toughness with good wear resistance PM tool steel. Typically hardness range of 58-64HRC with high temperature tempering.
Uddeholm Vanadis® 8 SuperClean: New Development for Trials PM steel, used in applications where abrasive wear resistance is critical. Typical hardness range is 58-62 HRC.
Uddeholm Vancron® 40 SuperClean:
Medium toughness with excellent resistance to galling. Typical hardness range 58-65HRC, with heat treatment similar to Vanadis 23.
Quick Overview of Tooling Materials
21
Choosing the right steel for your metalworking applications
Patricia Miller, Senior Technical Manager,
©2015 Bohler-Uddeholm
Uddeholm Vanadis® 4 Extra SuperClean
Choosing the right steel for your metalworking applications
Patricia Miller, Senior Technical Manager,
©2015 Bohler-Uddeholm
Forming Die for Producing a Bolt Fastener
Part
Vancron 40 coated with PVD Coating by Thermo Tech produced
500,000 parts and still running customer commented that the insert still looks GREAT!
Produced part
Bolt fastner part for Mid Sized trucks.
Sheet Steel
Uncoated HSLA Steel, Hytens 55 ksi,
Rm=350 MPa, HRPO t=5 mm
Tool Steel and Production Conditions
Uncoated Vancron 40 and D2 TD Coated
Dimension: 3.50 x 4.00 x 5.00”
Hardness: 60 HRC
Surface Roughness: Ra=0,1 um ?
Lubrication: 10% Oil Emulsion
Press speed: 60 parts/min
Galling / flaking of TD
coating on D2
Case Study: Vancron® 40 SuperClean
22
Choosing the right steel for your metalworking applications
Patricia Miller, Senior Technical Manager,
©2015 Bohler-Uddeholm
Application: Forming
Company: Presstran
Type of tool: Bolt Fastener
Work material: HSLA Hytens 55 ksi Thickness: 5mm
Process:
Case Study: Vancron® 40 SuperClean
Choosing the right steel for your metalworking applications
Patricia Miller, Senior Technical Manager,
©2015 Bohler-Uddeholm
Powder Metallurgy with Bohler MICROCLEAN ® Technology
K890 MICROCLEAN®:
Extremely high toughness in a PM tool steel: 3 Percent Vanadium Grade.
S693 MICROCLEAN®:
Good combination of wear resistance and ductility in a PM steel: high carbon PM M4.
K294 MICROCLEAN®:
Very high wear resistance in PM steel: a third generation PM A11.
S390 MICROCLEAN®:
Modified PM T15 with extremely high hardness capabilities and compressive strength.
Quick overview of Tooling Materials
23
Choosing the right steel for your metalworking applications
Patricia Miller, Senior Technical Manager,
©2015 Bohler-Uddeholm
Putting it all Together
Choosing the right steel for your metalworking applications
Patricia Miller, Senior Technical Manager,
©2015 Bohler-Uddeholm
Does your tool steel source produce the grades they
supply to you?
Do you know how the steel is being produced?
Do they address your concerns and provide corrective
action when you need it?
Do they create new grades to address your current and
future concerns?
Supplier’s contribution:
• Premium Grade Tool Steel
• Application-Designed Steel
• Full Technical Service
Critical questions…..just as with your work materials
24
Choosing the right steel for your metalworking applications
Patricia Miller, Senior Technical Manager,
©2015 Bohler-Uddeholm
47
UDDEHOLM VANADIS 8
SUPERCLEAN
General Comparison: Abrasive Wear Resistance vs. Toughness
Choosing the right steel for your metalworking applications
Patricia Miller, Senior Technical Manager,
©2015 Bohler-Uddeholm
Bohler W360 Isobloc®
Uddeholm Caldie®
Bohler K340 Ecostar®/Isodur®
Uddeholm Vanadis® 4 Extra
Hardness
Chipping
Resistance
Tool Steels for Good Chipping Resistance
25
Choosing the right steel for your metalworking applications
Patricia Miller, Senior Technical Manager,
©2015 Bohler-Uddeholm
Abrasive Wear
Uddeholm Vanadis® 8 SuperClean
Bohler K294 MICROCLEAN®
Adhesive Wear
Uddeholm Vanadis® 4 Extra SuperClean or
Uddeholm Caldie®
Combination
Bohler K340 Ecostar®/Isodur®
Uddeholm Vancron® 40 SuperClean
Tool Steels Used for Wear Resistance
Choosing the right steel for your metalworking applications
Patricia Miller, Senior Technical Manager,
©2015 Bohler-Uddeholm
Uddeholm Vanadis® 4 Extra SuperClean
Uddeholm Vanadis® 8 SuperClean
Uddeholm Vancron® 40 SuperClean
Add coatings when needed!
Improved
Galling
Resistance
Tool Steels Used for Galling Resistance
26
Choosing the right steel for your metalworking applications
Patricia Miller, Senior Technical Manager,
©2015 Bohler-Uddeholm
Uddeholm Vanadis® 4 Extra SuperClean
Bohler S693 MICROCLEAN®
Bohler S390 MICROCLEAN®
Tool Steels for High Compressive Strength
Choosing the right steel for your metalworking applications
Patricia Miller, Senior Technical Manager,
©2015 Bohler-Uddeholm
Total Tooling Economy: Bring all of your costs to the surface
27
Choosing the right steel for your metalworking applications
Patricia Miller, Senior Technical Manager,
©2015 Bohler-Uddeholm
Upgrading Your Tooling Performance with
Application Specific Heat Treatment and
Coatings.
Please join us for our next webinar in early 2016
Choosing the right steel for your metalworking applications
Patricia Miller, Senior Technical Manager,
©2015 Bohler-Uddeholm
Questions?
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