Prof Priit Kulu 2 Outline Highstrength structural steels Highperformance tool steels Metallicceramic materials Lightweight metals and alloys Superalloys Advanced metallic materials ID: 206785
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Slide1
Advanced metallic materials
Prof.
Priit
KuluSlide2
2Outline
High-strength structural steels
High-performance
tool
steelsMetallic-ceramic materialsLight-weight metals and alloysSuperalloys
Advanced metallic materials
2Slide3
3
Advanced metallic materials
3
Advanced metallic materials
Metallic materials with superior properties
Superconductive NbTi, Nb
3
Sn, Nb
3
Ge
Structural
alloys
Neodymium rare-earth magnets (
alloys
of Nd, Fe and B) are strongest known permanent magnets. Sm-Co magnets
Mg- and Al-alloys with superior properties, Al-metaglass, foams
Ti-alloys with thermomechanical properties, superalloys, maraging steels, intermetallides, high-density alloys, shape-memory alloys
Biocompatible Ti-alloys
Amorphous alloys with chemical and thermal properties, Ni- and Fe aluminates Slide4
4
Strength groups of materials
Classification based on tensile
strength (Rm) of materialsLow-strength (<250 N/mm2)Mid-strength (250...750 N/mm2)High-strength (750...1500 N/mm2)Ultrahigh-strength (<1500 N/mm2)
4
Advanced metallic materialsSlide5
5
Production technologies of hihg-strength steels and alloys
Advanced metallic materials
5Slide6
6
High-strength structural steels
High-performance
tool
steelsMetallic-ceramic materials
Light-weight metals and alloys
Superalloys
Advanced metallic materials
6Slide7
7
High-strength steel
...
what is it?The end of 1920-s Steel St 52 (S355) for bridge construction
Today
S355
is standard grade
Definition
for “high-strength”
is
dependent on level of development. Steel ReH > 355 MPa
7Advanced metallic materialsSlide8
8
Alloying of ferrite
Hardening
Ageing
Alloying elements, %
Ageing time, t
Methods for increasing strength
structure refinement
alloying – B; microalloying elements – Nb, Ti, V and N
low carbon steels
transgranular fracture
two- and multi-phase structures – F+M; F+M+B
dispersion strengthening – micro- and nanosteels
deformation
hardening:
- low- & high-temperature- isothermal
- marformingAdvanced metallic materialsSlide9
9
Heat treatable boron-steels
≈ 0,003% of B increased through-hardenability
0,002...0,003% of B in solid solution has the same effect on hardenability than 0,7% Cr; 0,5% Mo or 1% Ni
Through-hardenability diameter up to 200 mmC24CR Rp0,21000; Rm1500; A 7%
9
Advanced metallic materialsSlide10
10
Low-alloy high-strength steels
Also known as HSLA steels
C = 0,2..0,3% ; alloying el: Mn, Si
Micro alloying with Nb, Ti and/or V – dispersion strengthening + grain refinementHX340LADHX460LADRp0,2560; Rm640 N/mm2; A – min 15%
10
Advanced metallic materialsSlide11
11
Two- and multi-phased steels
Also known as duplex (DP) and complex (CP) steels
Ultra-High-strength (UHS) ductile steels
Two-phase LITEC DP Rp0,2750 N/mm2; Rm980 N/mm2; A – min 10%
11
Advanced metallic materialsSlide12
12
→
good formability and high strength
→ ability of high energy absorption→ high strain-hardening rate→ good fatigue strength
DP-steel
CP-steel
12
Advanced metallic materials
-
Multi-phase
LITEC CP
R
p0,2
900; R
m
980 N/mm2; A – 7%Slide13
13
Maraging (martensite-ageing) steels (1)
Martensitic steels (
C%)
low ductility and toughness in case of high RmM decomposition, formation of carbide phase brittlenessMaraging steels in 1980low C-content (0,03%) transgranular fractionalloying el. – Ni (17...25%), Mo + Ti, Al, Ta etc. Quenching C-free martensite,
Ageing intermetallides (4 – 5) nm, (NiTi, Ni3Ti, NiAl, Ni
3
Mo etc.)
R
m
2000
N/mm
2
, R
p0,2 1500 N/mm2
, A = 10 - 12%13Advanced metallic materialsSlide14
14
Maraging steels (2)
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Advanced metallic materialsSlide15
15
Termomechanically processed /
deformation hardened
15
Advanced metallic materialshigh temperature
low temperature
isothermal
marformingSlide16
16
Thermomechnical rollingSlide17
17
TRIP-steels (Transformation Induced Plasticity)
Low alloy steels (car industry)
0,2 – 0,3 % C; 1,5 – 2,0 % Mn, Si + Al
High alloy Ni-Cr steeks0,2 – 0,3 % C; 8 – 32 % Ni; 8 – 14 % Cr+Mn (0,5 – 2,5%), Mo, SiQuenching (985 – 1200 °C) → F, B, ADeformation (< Trecr = 250 – 550 °C), A → MRm →1700, Rp0,2 → 1550, A =50 – 60 %, ↑KIC, σ-1Slide18
18
Strength-plasticity of high-strength steels
TMT + def. ageing
KTMT
TMT + def. ageing
Low-alloy steels
Maraging steels (high-alloy)
R
p0,2
N/mm
2
2000
1000
20
40
60
60
A%
TRIP-steelsSlide19
19
High-strength structural steels
High-performance
tool
steelsMetallic-ceramic materialsLight-weight metals and alloys
Superalloys
Advanced metallic materials
19Slide20
20
Advanced tool
steels
(1)
I generation of high-speed steels (HSS)carbide temper hardness steels 500 - 650 0C, e.g. HS 6 – 5 – 2 – 5W-Mo -V –CoIntermetallic temper hardness steels650 - 750 0C, Co7W6, (CoFe)7W6 etc.(11 – 20%)W; 7% Mo; (1-3%)V; (20 – 25%)CoStructure (cast and rolled)
20
Advanced metallic materialsSlide21
21
Advanced tool
steels
(2)
II generation of high-speed steels – PM steels (PM/HIP)Uddeholmi steels Vanadis 4, 6, 10, 23, 30, 60 (Super Clean) (1,3 - 2,9%) C; → 6,5 W; (1,5 - 7%) Mo; (3,1 - 9,8%) V; → 10,5% CoStructure (PM / HIPed)
21
Advanced metallic materialsSlide22
22
Advanced tool
steels
(3)
III generation of high-speed steels – Sprayformed, SF + HIP PM steels, Vanadis 4 EXTRAWEARTEC 2,8 C; 8,9 V; 7,0 Cr; 2,3 Mo; Si; MnROLTEC 1,4C; 4,6Cr; 3,7 V; 3,2 Mo; Si; MnTOUGHTEC 1,6C; 7,2V; 5,0 Cr; 2,3 Mo; Si; Mn
22
Advanced metallic materialsSlide23
23
SF /HIP
Similar
to
PM/HIP, slab formation by spraying methods23
High-Tech Materials & TechnologiesSlide24
24
Strength of
high-speed steels
TRZ, GPa
Diameter of carbide particles, m
24
Advanced metallic materialsSlide25
25
High-strength structural steels
High-performance
tool
steelsMetallic-ceramic materialsLight-weight metals and alloys
Superalloys
Advanced metallic materials
25Slide26
26
Classification of wear resistant materials depending on volumetric content of hard phase
Advanced metallic materials
26Slide27
27
Metallic-ceramic composites
Carbide steels and alloys
Ferro-TiC
Steel (50 - 70)% -TiCDouble-reinforced MMC (Cr-steel + 20%VC) + 20%WCSelf-fluxing alloysNiCrSiB + 50% (WC-Co)Ceramic/metallicTiC-NiMo – (50 - 60)% (NiMo)(2:1) 920 – 1620 HV10Cr3C
2-NiCr – (50 - 60)% NiCr
27
Advanced metallic materialsSlide28
28
High-strength structural steels
High-performance
tool
steelsMetallic-ceramic materials
Light-weight metals and alloys
Superalloys
Advanced metallic materials
28Slide29
29
Light-weight materials – Mg alloys
Mg-alloys
(Mg:
= 1740 kg/m3, Ts – 649 0C)Alloying elements: Al (3 - 10%); Zn, up to (5 – 6%); Mn; ZrRm 300 N/mm2 (deformable alloys) Rm/ 20
220 N/mm2 (cast alloy)
29
Advanced metallic materialsSlide30
30
Light-weight materials –
Al alloys
Al-alloys
Al-Li alloys (Li is only dopant, which Rm, E, however = 2500 kg/m3) 2Li, 4Mg, Rm = 220 – 350; Rp0,2 = 135 – 210 N/mm2Powder-aluminum-alloys
dispersion strengthened Al-alloys (SAP-Al2O3
15%, Al-C-alloys – Al
4
C
3
20 volume%), allowed
working temperature up to 550
0
C
Foam-aluminum ( ~ 200 kg/m3)
30Advanced metallic materialsSlide31
31
High-strength structural steels
High-performance
tool
steelsMetallic-ceramic materials
Light-weight metals and alloys
Superalloys
Advanced metallic materials
31Slide32
32
Superalloys
…alloys capable of service at high temperatures, usually above 1000
°C
→ heat-resistant high-temperature strength alloysNi-alloysCo-alloysheat resistance (oxidation resistance > 600°C)refractory steels = heat res. + high temp. strength32
Advanced metallic materialsSlide33
33
Ni-alloys
Ni uses:
ca
60% – stainless steels 12% – Ni-alloys 10% – coatings 10% – alloy steels Heat resistant alloys (superalloys)wrought (Inconel Ni – 20-23 Cr; Hastelloy Ni- 7-22 Cr-Co)cast ( polycrystalline, directionally solidified, single crystal)PM (HIP-ed, IN 100, Rene 95→ gasturbine disk)718 (cast) Ni – (4,75 – 5,5%) Nb → aerospace, nuclear structuralapplications (-250 – +700
°C).MA 754 PM/HIP Ni – 1% Y
2
O
3
33
Advanced metallic materialsSlide34
34
Co-alloys
Co uses:
ca
46% – superalloys 15% – steels 10% – cemented carbidesWear resistant alloysStellite – Co (10 –30%); Cr (1,5 –22) Ni; up to 15% W; 1 MoHeat resistant alloyswrought Co + (20 –30%) Cr; (14 –15%) Wcast Co +(23 –29%) Cr; (1 –10 %) Ni; 7 WCorrosion resistant alloysUltimet Co + 26Cr; 9Ni; 5Mo; 2W
34
Advanced metallic materialsSlide35
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General stress-rupture behaviour of superalloysSlide36
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Thank you for your attention!
TUT materials engineering web-site
:
www.ttu.ee/mtimti@ttu.ee