Advances in Wear Resistant Alloys and

Products

Jim Wu, Ph.D.Jim Wu, Ph.D.

CTOCTO

Deloro Stellite GroupDeloro Stellite Group

Outline

� Types of Corrosion and Wear Resistant Alloys (Co and Ni Alloys)

� Newly Developed Alloys� Applications

� Cobalt based alloys� Nickel based alloys� Alloy Composites

Wear and Corrosion Resistant Alloys

Cobalt Alloys – Type 1

� Type 1 – Carbide Alloys� High carbon ( > 0.8% )� Carbide particles: M7C3 and M23C6

� Resistant to wear and corrosion at temperatures below 600º C.

4629Cr-8.5Mo-1.6C712

4229Cr-4.5Mo-1.2C706

4229Cr-4.5W-1.2C6

HRCNominal CompositionAlloy

Powder, Rod, Wire, P/M and Casting

Wrought Products – 6B, 6K, 706K

MicrostructuresType 1 Cobalt Alloys

Hypo-eutectic Hyper-eutectic

Carbide Shapes in Hyper-eutectic Stellite Alloy

30 µ

Longitudinal Transverse

SEM Micrograph (BEI)Type 1 Alloy – 712 (Mo-Containing)

Cr in dark areas (M23C6) and Mo in light areas (Mo6C)

05

101520253035404550

29Cr-1.2C-4.5X 29Cr-2.4C-12X

Co

rro

sio

n R

ate

in m

m/y

ear

W-Containing Alloy Mo-Containing Alloy

X=W

X=W

X=MoX=Mo

Corrosion Test Results in 10% H2SO4 @ 66º C

0 10 20 30 40 50 60

Stellite-12

Stellite-712

Volume Loss in mm3

ASTM G65 Wear Test Results

Piston for Downhole DrillingStellite 712 Overlay

Oil Drilling PistonStellite 706 PTA

ValvesStellite 6 Overlay

Z-Notch

Gas Turbine BladesStellite 694 Overlay on Z-Notch

Fretting Wear

PTA Hardfaced Extrusion Screws

Tri-Cone Drill Bits

Journal

Thrust Face

Pilot Pin

(Hardfaced with Type 1 Co Alloy)

Cobalt Alloys – Type 2

� Type 2 – Intermetallic Alloys (Originally developed by DuPont)� Hard Laves phase: Co3Mo2Si and CoMoSi, low carbon content� Stable up to 800º C� For high temperature wear and highly corrosive wear

5427Mo-14Cr-2.6Si-0.1CT-400C

48Hypo-eutectic (most ductile)T-401*

5423Mo-17Cr-16Ni-2.7Si-0.04CT-900

5828Mo-17Cr-3.4Si-0.04CT-800

5528Mo-9Cr-2.6Si-0.04CT-400

HRCNominal CompositionTribaloy

* Patent pending

Powder, Rod, Wire, P/M and Casting

SEM Micrograph (BEI)Type 2 Cobalt Alloy (T-400C) - Casting

Primary Laves Phase

SEM Micrograph (BEI)Type 2 Cobalt Alloy (T-900) – PTA Weld

SEM Micrograph (BEI)Type 2 – Hypo-eutectic (T-401) - Casting

Secondary Laves Phase

Hot Hardness

0

100

200

300

400

500

600

700

800

0 250 500 750 1000 1250 1500

Test Temperature, °F

Hot

har

dnes

s, H

VT400440C712Stellite 6

Cast Tribaloy T-400 Actuator for Turbochargers

Kocks mill rollsHardfaced with T-900 for rolling W rods

Corrosion Test Results by Teck Cominco

GI Bath – 0.22%Al, saturated with Fe, at 470°C

T-401 or T-800 Galvanizing Bushing

Cobalt Alloys – Type 3

� Type 3 - Solid Solution Alloys� Solid solution strengthened with a few carbide particles� Strong work hardening� High corrosion resistance

38CoCr-12Mo28*

3226Cr-11Ni-7.5W-0.5C31 (X40)

2725Cr-9Ni-5Mo-2W-0.05CUltimet

2828Cr-5Mo-0.25C21

HRCNominal CompositionAlloy

* Patent pending

Powder, Rod, Wire and Casting

Phase TransformationBSED Pattern

Phase Transformation of a Type 3 Alloy under Stress

Valve StemStellite 21 PTA

Stellite 21 Forging Dies (HIP’ed)

Application: Automotive torsion bars

Previous Die Material: H13

Previous Life: 2000 hits

Current Material: Stellite 21 HIP

Current Life: 38,000 hits

(Coated with TiN but not necessary)

Ultimet

Thick PTA Overlay

Ultimet Overlay by Laser Cladding on Offshore Drilling Platform

Tensioners

Stellite 28 Laser Clad (0.5” thick)Hardness: HRC 47-48

Comparison between Stellite 28 and 21

<45 C70-75 CCritical Pitting Temperature (ASTM G48C)

7660Abrasion G65 Vol Loss in mm3

HRC 33HRC 38PTA Overlay Hardness at Room Temp

5.5%12%Mo Content

Stellite 21Stellite 28

Weld Repair of Stellite 28 PTA Overlay

No Preheat, No Filler

150°C Preheat, Stellite 6 rod

No Preheat, Stellite 6 rod

Rod Dia: 3.2 mm

Other Co Alloys under Development

� Stellite 6A – Anti-aging� Stellite 21LA – Very tough laser clad and PTA overlay

� Laser - 6.5 times as Stellite 21� PTA -1.5 times as Stellite 21

� Stellite 24 – Hot Metal-working� Stellite 300 – High abrasion resistance at HRC 62, designed for hot dip

coating applications.� Tribaloy SF T-400 – Spray and fuse version of T-400

Abrasion Test Results of Investment Cast Samples

ASTM G65 Procedure B Abrasion Test

0

10

20

30

40

50

60

70

Har

dn

ess

HR

C o

r V

olu

me

Lo

ss m

m3

Hardness

Volume Loss

Hardness 39 55 61 62

Volume Loss 19.6 18.1 5.1 4.9

Stellite 6 T-800Stellite

80Stellite

300

� Boride Alloys: 1-4% B� Deloro Alloys – Rod and Powder

� Silicide Alloys: 5-7% Si� Nucalloy Alloys – Rod and Powder

� Intermetallic Alloys: C+B < 0.1%� Tribaloy T-700 - Powder

� Solid Solution Alloys: C+B < 0.4%� Ni-Cr Alloys

Nickel Alloys

Castings can be made with most of these alloys.

Solid Solution Ni Alloys

� Nistelle (Hastelloy) alloys� B, C, 625 and others – Powder and Wire

� Nistelle Super C� Ni-23Cr-18Mo - Powder

Castings can be made with most of these alloys.

Corrosion ResistancePTA All-Weld Specimens

0.975

0.521

0.668

0.1270.005

0.224

0.000

0.200

0.400

0.600

0.800

1.000

1.200

10% H2SO4 @boiling

5% HCl @ 66C 65% HNO3 @ 66C

Co

rro

sio

n R

ate

in m

m/y

ear

Nistelle C Nistelle Super C

� Contain 45-50% Cr.� Highly corrosion resistant.� Used successfully in handling black liquor in pulp mills.

(cast pipes)� Used successfully with thermal spraying in preventing “fire-

side” corrosion in power gen boilers.

Ni-Cr Alloys

Powder, Wire and Casting

� Alloy MatrixCo, Co+Cr, Ni, Ni+Cr, and Other Alloys

� Hard ParticlesCarbides

� Product FormsPowders and tube wires

Alloy Matrix Composites (AMC)

Wear Resistant Carbide Overlays/Coatings

� PTA Overlays� Carbides in Ni or Co alloys

� HVOF Coatings� Carbides in Co or Ni or their alloys

� GTAW (MIG) Overlays� Carbides in Ni or Co alloys

� TUNGSTEN CARBIDE - WC: 6.1% C - WC+W2C: 3.9% C

� VANADIUM/TUNGSTEN CARBIDE - (V,W)C: 13% C, 57% V, 23% W

� CHROMIUM CARBIDE- Cr3C2: 10% C

Carbides

W2C 3000 DPHWC 2400 DPHVC 2800 DPHTiC 2800 DPHCr7C3 2100 DPH

M7C3 (Co) 1600 DPHM7C3 (Fe) 1500 DPH

Hardness of Carbides

Characteristics of AMC

� Excellent abrasion resistance� Bonding between matrix and carbide important to wear

resistance� Carbide integrity important too

� Precipitation of WC very sluggish

� TiC easy to oxidize

Erosion Test Data at 700 C (Solid Particle Erosion)

Erosion Testing, 700 deg.C, 60-deg

0 0.01 0.02 0.03 0.04 0.05 0.06 0.07

AISI 410

410 + TMT Coating

AISI 304H

304H+TMT coating

902

Super Stelcar 50

Stellite + 70%CrC

Stellite 12

Stellite 6

Stellite 1

Stellite 712

Stellite+ 50%CrC

Tribaloy T800

Stellite 720

Stellite + 20%TiC

Weight loss mg/g of erodant

Thermocouple SheathStellite 712 TiC Composite

PTA Weld Overlay of WC in NiSiB

AMC PTA Overlay

Equipment for Tarsand Excavation

Screens for Tar Sand Processing

AMC PTA Overlay

Product Forms of Wear Resistant Alloys

� Components� Castings� Powder Metallurgy Parts

� Wrought Products (Stellite 6B, 6K, 706K)

� Hardfacing Consumables

Hardfacing Consumables

� Cast rods for GTAW (TIG) or Oxyacetylene weld overlaying.� Coated Electrodes for SMAW.� Tubular or solid wires for GMAW (MIG) or GTAW overlaying. � Powders

� Flame spray and fuse.� Plasma transfer arc (PTA) weld overlays.� HVOF thermal spray.� Laser cladding.� HIP cladding or HIP’ing.

Effect of Different Overlaying Process

0

10

20

30

40

50

60

0 0.1 0.2 0.3 0.4 0.5

Distance from bond line

Fe

%

PTA Weld GTA (TIG) Weld

05

101520253035404550

Stellite-6 6% Fe 10% Fe 20% Fe

Har

dnes

s R

c

22204427538649760

Effect of Dilution on Hardness at Various Temperatures

Temp °C

As temp increases, effect of Fe dilution increases.

Surfacing Equipment

� Plasma Transferred Arc Welding� High Velocity Oxyfuel (HVOF) Thermal Spraying

� Automotive� Chemical Processing� Food � Wood Cutting� Waste Incineration� Glass� Pulp and Paper

� Power Generation� Fossil fuel

� Coal fired� Nuclear

� Hydropower

� Oil Drilling and Refining� Medical and Dental

� Steel Mills

Industries Served

� Deloro Stellite has a large portfolio of alloys in components and hardfacing consumables.

� Deloro Stellite is capable of providing alloy solutions for most of wear/corrosion problems.

Concluding Remarks