Laser Based Deposition of Stainless Steel Alloys

CIMP-3D
CIMP-3D
CIMP-3D
Laser-Based Deposition of
Stainless Steel Alloys
Rich Martukanitz
Center for Innovative Materials Processing through Direct Digital Deposition,
Pennsylvania State University
(www.cimp-3d.org)
Presented at the American Welding Society’s Conference on
Stainless Steel Welding
Philadelphia, PA
March 26, 2014
AGENDA

Background on Laser Deposition Technology

Applicability to Stainless Steel Alloys

Examples

Summary
BACKGROUND
Legacy of the Applied Research Laboratory in Laser Deposition Technology
1990
1995
2000
2005
2010
In-Situ Processing at
Pearl Harbor NSY
Laser Deposition of Tooling Material at
Alvord Polk Corp.
Martensitic SS – TiC
Multi-Deposit of
Fe48Cr15Mo14Y2C15B6
Laser Repair of
Marine Components
(NUWC-Keyport and
Puget Sound NSY)
Laser-Based Deposition of
Tooling Grade Material
(Alvord Polk Corp.)
Laser Deposition for
Commercial
Applications
(Caterpillar Corp. and
Bonney Forge Corp.)
Laser Free Forming Under
DARPA Support
(Aeromet Corp.)
Improved Fundamental
Understanding
of Processes
Crystalline
Laser Deposition of Aluminum Alloy at
the NUWC-Keyport
Advanced Coating
Materials
BACKGROUND
Applications of Deposition or Additive Manufacturing of Metallic Materials
Additive Manufacturing
Processes
Producing a
Unique Material
Surface
Deposition
Deposition of Fe-10Cr-13P-7C
BMG
Bulk
Deposition
Creation of Ceramic Eutectic
Structures Through Selective Laser
Melting
Modifying
a Surface
New Part
Laser Deposition of Tooling-Grade
Material
at Alvord Polk Corp.
Repair or
Restoration
Producing a
Component
2D
Courtesy of ARL Penn State
Courtesy of ARL Penn State
3D
Courtesy of ARL
Penn
State
Morris
Technologies
Courtesy of ARL Penn State
Deposition of Transparent Conductive
Oxide (TCO) courtesy of Laserod Inc.
Courtesy of ARL Penn State
Courtesy of Sciaky
BACKGROUND
Processes for Additive Manufacturing of Metallic Materials
Directed Laser Deposition
Defocused Beam
Coaxial
Gas
 Laser-based coating and deposition processes
may be used to:
– impart higher hardness on the surface for
improved wear resistance
Powder
Feed
Powder
Feed
Laser Deposit
Substrate
– locally alter the composition at the surface for
improved corrosion resistance
– restore dimension tolerance
 These processes:
– may employ a wide variety of lasers
– may utilize pre-placed powder, a precursor layer,
direct-placed powder, or axial fed powder
– use various techniques to enlarge the interaction
area for increased surface coverage
Technical Plans
BACKGROUND
Processing Systems and Characteristics of Laser Deposition of
Metallic Materials
 Laser Deposition Provides:
LENS MR-7
– moderate to very good feature definition
– moderate deposition rates (0.5 - 10 kg per
hour)
– strong metallurgical bonding to the
substrate
DM3D1
EOS M 280
– dilution of the substrate of between 5 and
40%
– low heat input, which may provide:
Courtesy of Morris Technologies
 refined microstructure of deposit
HPHD
 low thermal distortion of the substrate
 high cooling rates within the substrate
 Laser Deposition is applicable to a wide
assortment of metals
1
Photographs courtesy of DM3D Corporation, Auburn Hills, MI
Technical Plans
BACKGROUND
Metallic Material Systems for Additive Manufacturing
 Aluminum alloys (AA 2319, 4047, 5356)
–
low density, moderate strength, and high thermal conductivity
 Cobalt-Chrome alloys (Commercial designation Stellite 6, Stellite 12, Haynes 6B)
–
high hardness and corrosion resistance
–
medical implants
 Nickel alloys (Commercial designation Inconel 625, Inconel 718, Hastelloy C-276)
–
good room temperature corrosion resistance and good elevated temperature oxidation resistance
 Refractory alloys (W, Nb, Ta)
–
high melting point alloys, such as tantalum, niobium, and tungsten
 Stainless steels (ASTM 308L, 309L, 316L, 420, 426, 431)
–
wide range of properties and applications
 Titanium alloys (CP, Ti6Al4V, Ti6Al4V ELI)
–
aerospace and medical implants
 Tool Steels (AISI A6, H12, H13)
–
tool and die repair
Technical Plans
BACKGROUND
Additional Consideration for Deposition of Metallic Materials
10 mm
10 mm
50 mm
120 mm
10
Courtesy of Sciaky
6
1000
2
4
100
Feature Quality (m)
8
10
Deposition Rate (kg/hr)
10 mm
100 mm
2
4
6
8
Beam Power (kW)
10
12
14
Technical
Plans
APPLICABILITY TO STAINLESS
STEELS
Laser Deposition of a Metallic Material
Slightly Diffuse Beam
Deposit from
Powder Layer
HAZ
 Laser deposition processes involve the
addition of material that is melted onto the
substrate and results in metallurgical
bonding
 Powder is typically used as the added
material
Substrate
– high absorption of laser energy
– available form for specialized materials
– may be blended
 A small heat affected zone is created
within the substrate directly below the
deposition
Laser coating of Inc625 on HY-100
Technical
Plans
APPLICABILITY TO STAINLESS
STEELS
Product Forms of Metallic Materials for Laser Deposition
U.S. Sieve
Size
Sieve
Opening
(m)
80
177
100
149
140
105
170
88
200
74
230
63
270
53
325
44
400
37
 Directed laser deposition systems primarily use
powder material:
–
higher energy absorption associated with powders
–
wide range of powder suppliers and alloys available
–
powder size used for this process has historically been -100
+ 325 mesh (44-149 m)
 Wire feedstock may also be used:
–
high quality material available as welding consumables
Technical
Plans
APPLICABILITY TO STAINLESS
STEELS
Micrographs and Microhardness of Commonly
Used Metals for Wear and Corrosion Resistance
Micrograph of Inconel 625 Laser Clad
Micrograph of 431 SS Laser Clad
Microhardness (VHN, 500 gf)
Micrograph of Stellite 6 Laser Clad
600
High
Low
Average
500
400
300
200
100
0
Stellite 6
Inconel 625
Powder Types
431 SS
Technical
Plans
APPLICABILITY TO STAINLESS
STEELS
General Continuous Cooling Transformation (CCT) Diagram for Steels1
1
http://commons.wikimedia.org/wiki/File:CCT_curve_steel.svg
Technical
Plans
APPLICABILITY TO STAINLESS
STEELS
Carbon Content (%)
Graville Diagram for Sensitivity to Hydrogen Assisted Cracking
Zone 2
Depends Upon Welding
Conditions
431
Zone 3
High Under All Welding
Conditions
Zone 1
Safe Under Most Conditions
Carbon Equivalent (CE)
CE = %C + %Mn/6 + %Ni/15 + %Cr/5 + %Mo/4 + %V/5
For AISI 431 stainless steel:
CE1045 = 0.20 (C) + 0.1.0/6 (Mn) +2/15 (Ni)= 0.50
EXAMPLES


Example 1
−
restoration of dimensional tolerances for a 1045
forging for undersea system
−
added materials were Stellite 6 (internal diameter)
and 309L stainless steel (outer diameter)
Example 2
−
development of a deposition system for repair of
carburized and chromium electroplated surfaces
−
applicable to a wide range of drivetrain
components
EXAMPLE 1
Dimensional Restoration of Large Forging

Example 1
−
restoration of dimensional tolerances
for a 1045 forging for undersea
system
−
deposited materials were Stellite 6
(internal diameter) and 309L stainless
steel (outer diameter)
−
dimensional requirements were +
0.001 in. (25 m)
EXAMPLE 1
Dimensional Restoration of Large Forging
EXAMPLE 1
Characteristics of 309L and Stellite 6 Deposits on 1045 Steel
L
The dilution of the 1045 base metal resulting from the laser deposition process, based on the macrograph of Figure 19, was estimated to be
approximately 60% for this single pass deposit. Based on this dilution and the nominal composition of 0.03% carbon in the 309L alloy and
the 0.45% carbon in the 1045 alloy, a carbon content of approximately 0.29% would be anticipated in the laser deposit. According to data
provided by Timken Corporation from Jominy quench tests, a steel having a carbon content of 0.29% would result in an as-quenched
hardness of approximately 41 HRC. Conversion of the 41 Rockwell C hardness to Vickers hardness yields 402 VHN, which is similar to the
hardness observed in the single pass SS309L deposit.
EXAMPLE 2
Emulating Carburized and Chromium Surfaces Through Laser Deposition
 The ability to emulate characteristics of unique surfaces
through laser deposition offers a huge opportunity to
repair high value components:
− carburized surfaces
− chromium electroplated surfaces
 A viable repair process and replacement material must
consider:
− hardness and wear resistance,
− corrosion resistance, and
− tribological effects
 Prior work had indicated the potential of a composite
materials system for meeting this goal
EXAMPLE 2
Development of a Composite Deposition Material
Diagram for WC and TiC in SS431
 Simulations were used to
identified materials systems for
addition to a martensitic grade stainless
steel matrix material (alloy 431):
– TiC
– TiC and TiC with reactive shielding
Kinetics of WC and TiC in SS431
 These systems rely on composite
strengthening and re-precipitation
of fine, stable particles
 The theoretical predictions require
validation by laser deposition
experiments
EXAMPLE 2
20 w 0 TiC in a Martensitic Grade of Stainless Steel (Alloy 431)
20 Ar
18 Ar – 2 N2
Air
EXAMPLE 2
20 w 0 TiC in a Martensitic Grade of Stainless Steel (Alloy 431)
20 Ar
18 Ar – 2 N2
Air
EXAMPLE 2
Hardness of SS 431 and 20 w 0 TiC Deposits With Reactive Shielding
EXAMPLE 2
Laser Deposits of TiC/431 on Mild Steel in Argon
No cracking
Cracking during second layer
Cracking during first and second layer
EXAMPLE 2
Process Parameters for Laser Deposition of Component
Representing 8620 Alloy
Deposition
Material
Laser
Power
Spot
Size
Travel
Speed
Powder Flow
Rate
Hatch
Spacing
Environment
20% TiC/431
1000 W
2.5 mm
1 cm/s
7 g/min.
1.5 mm
Argon
EXAMPLE 2
SS 431/20 wt% TiC Laser Deposited on Carburized 8620 Steel in Argon
Range for carburized and chromium
electroplated surfaces
•
Single layer SS 431/20 TiC composite deposited
on 8620 steel provides slightly higher hardness
than carburized layer
•
The interface and deposit exhibited excellent
quality with no cracks or discontinuities within the
deposit or interface
EXAMPLE 2
Energy Dispersive X-Ray Analysis of Deposit Representing
SS 431 With 20 wt% TiC on Carburized 8620 Steel
EDS elemental mapping analysis
A
B
Chemical Composition
Elements (wt%)
Fe
Cr
Ti
Ni
Mn
C
Si
8620 Base
96.33
0.49
-
0.34
0.65
1.81
0.38
HAZ
94.94
0.73
0.14
0.44
0.66
2.55
0.53
A. Deposit (White Area)
85.82
4.55
2.68
0.54
0.5
4.87
1.03
B. Deposit (Black Dot)
59.65
3.67
23.2
0.42
0.32
11.73
1.03
Summary
 Laser-based repair processes may be used to deposit a
wide range of stainless steel alloys
− wear and corrosion resistance
− dimensional restoration
 Weldability plays an important role in selection of
stainless steel alloys for laser-based deposition
 Deposits produced using a martensitic stainless steel
alloy with 20% (wt.) TiC provides hardness similar to a
carburized and chromium electroplated surface

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