sldi - hitachi metals · 2016. 10. 1. · o500 c 2h+2h good poor grade chemical composition (wt%)...
TRANSCRIPT
SLDi
June 2016
Hitachi Metals America
1 | Hitachi Metals America, LLC | All rights reserved |
2 | Hitachi Metals America, LLC | All rights reserved |
1.1 Sheet Metals Trends
IF
200 400 600 800 1000 1200 1400 1600 0
10
20
30
40
50
60
70
Elo
ng
ati
on
(%
)
Tensile Strength MPa
Cast Iron S7 / A2 / D2 Advanced Grade / Hot Stamp
~1995
1995~2000
2000~2015
2015~
AHSS use is increasing due to automotive light-weighting. Advanced
die grades are needed to form AHSS.
3 | Hitachi Metals America, LLC | All rights reserved |
1.2 Tool Steel Bubble Chart
SLD-i™
D2
A2
S7
8%Cr steel
4 | Hitachi Metals America, LLC | All rights reserved |
Grade Chemical composition (wt%)
C Si Mn Cr Mo V Others
D2 1.40-
1.60
0.30-
0.50
0.30-
0.50
11.0-
13.0
0.70-
1.20
0.50-
1.10 -
SLD-i™ Within the D2 spec (stricter) -
8%Cr Steel* 1.0 1.0 0.4 8 2 0.3 -
SLD-MAGIC® Same as
8%Cr Steel
Same as
8%Cr Steel
Same as
8%Cr Steel
Same as
8%Cr Steel
Lower than
8%Cr Steel
Lower than
8%Cr Steel Addition
*Chemical composition of 8%Cr Steel has a variety by steel maker
2.1 Chemical Composition
5 | Hitachi Metals America, LLC | All rights reserved |
2.2 Microstructure 8%Cr Steel SLD-i™ D2
Small, dense & homogeneous
carbide distribution will
contribute to
• Small & isotropic heat
treatment deformation
• Good galling & wear
resistance
Coarse & directional carbide
distribution
• Large & anisotropic heat
treatment deformation
• Medium galling & wear
resistance
• Characteristics will be
affected by grain direction
Small & sparse carbide
distribution
• Large heat treatment
deformation
• Low galling & wear
resistance
• Good toughness &
machinability
200μm 200μm 200μm
6 | Hitachi Metals America, LLC | All rights reserved |
2.3 Heat Treatment Condition
Tempering curve Retained austenite
If γR is less than
5%, secular
change risk will be
minimized.
*Quenching:1030C (1886F)
SLD-i
D2
Hard
ness
Tempering temperature ℃ x2hr x 2 times Tempering temperature ℃ x 2hr x 2 times
Maximum
hardness at 500C
(932F) temper.
Compared to D2, SLD-i is capable of an equal or greater hardness with the same
heat treatment.
500oC (932oF) tempering temperature maximizes SLD-i performance due to;
Obtaining maximum hardness (over 60 HRC).
Lowering γR below 5% (minimize secular change risk).
7 | Hitachi Metals America, LLC | All rights reserved |
2.4 Heat Treatment Deformation
0
0.01
0.02
0.03
0.04
0.05
0.06
0.07
SLD-i D2
Dim
en
sio
na
l C
ha
ng
e (
%)
Length
Width
Specimen size:
18Tx25Wx30L(mm)
Austenitizing:
1030oC
Tempering:
500oC 2h+2h
Good
Poor
Grade Chemical composition (wt%)
C Si Mn Cr Mo V
D2 1.40-
1.60
0.30-
0.50
0.30-
0.50
11.0-
13.0
0.70-
1.20
0.50-
1.10
SLD-i Within the D2 spec
Reference: Chemical composition of SLD-i is within the D2 spec
8 | Hitachi Metals America, LLC | All rights reserved |
3.1 Case Study Punch dies for burring hub bearings
Spec 73.86±0.01 mm
SLD-i Sample 1 73.863 mm
Sample 2 73.856 mm
Sample 3 73.859 mm
Sample 4 73.867 mm
Sample 5 73.859 mm
Pass rate 100% (5/5)
Pass rate of D2 10% OD: 75mm
Application Grade Coating Die life
Punch dies
for burring
SLD-i™ TD coated More than 500,000 hits
WITHOUT repairing
D2 TD coated 10,000 – 100,000 hits with
repairing
9 | Hitachi Metals America, LLC | All rights reserved |
3.2 Case Study Shear Tool for 1500 MPa
Application Grade Hardness Coating Die life before re-
sharpening
Shear Tool SLD-i™ 60~62 HRC Bare surface 75,000 ~ 100,000 cuts
D2 60~62 HRC Bare surface 10,000 ~ 15,000 cuts
Application Cross Member
Floor Panel Part
Thickness 1.5 mm
Hardness 52 HRC
Strength 1500 MPa
Failure mode of dies Wear/Galling
Material information
10 | Hitachi Metals America, LLC | All rights reserved |
Item Condition
Test
piece
Grade
D2, SLD-i,
SLD-Magic
and 8Cr
Hardness 60HRC
Disc Alumina
Surface pressure 7.8 MPa
Friction Speed 0.42 m/sec
Friction length 377 m
<Conditions> <Results>
Good
Poor
ASTM G99-05
TP Disc 0
1
2
3
4
5
6
7
8
9
D2 SLD-i 8%Cr SLD-MAGIC
Wea
r V
olu
me
(x 1
0-1
4m
2/
N)
SLD-i™ SLD-MAGIC® 8%Cr Steel
Increase carbide
amount
→Decrease
Wear amount
4.1 Wear Resistance
11 | Hitachi Metals America, LLC | All rights reserved |
Initiation point and
direction of galling
Load
Bead
Punch Die
Work piece
Schematic diagram of test condition
<Results> Item Condition
Length of Stroke 60mm
Pressing Velocity 60spm
Lubricant Rust prevention oil
*delivery condition
Work 980MPa HSS
Work Thickness 1.4mm (No Zn plating)
Clearance:5%
Die surface
condition
Polished by #8000 paper
(2-4μm)
<Conditions>
0
500
1000
1500
2000
2500
3000
3500
D2 SLD-i 8%Cr SLD-MAGIC
Hold
ing P
ressure
(kg・f)
SLD-i™ SLD-MAGIC ® 8%Cr Steel
4.2 Galling Resistance
THANK YOU