Energy efficient manufacturing
chain for advanced bainitic steels
based on thermomechanical
processing
Prof. Dr. Alexandre da Silva Rocha, Laboratório de
Transformação Mecânica – UFRGS
Prof. Dr.-Ing. Hans-Werner Zoch – Stiftung Institut für
Werkstofftechnik - Bremen
Slide 2
UFRGS - Porto Alegre working team:
Prof. Dr. Alexandre da Silva Rocha
Prof. Dr. Rafael Menezes Nunes
Prof. Dr. Lírio Schaeffer
Prof. Dr. Afonso Reguly
Prof. Dr. Nestor Heck
Dr. Eng. Alberto Guerreiro Brito
Msc. Rafael Luciano Dalcin
Msc. Rodrigo Afonso Hatwig
Msc. Thiago Marques Ivaniski
Eng. Antonio Carlos de Figueiredo Silveira
Eng. Tâmie de Souza Perozzo
IWT - Bremen working team:
Prof. Dr.-Ing. Hans-Werner Zoch
Dr.-Ing. Jérémy Epp
Dr.-Ing. Matthias Steinbacher
Dr.-Ing. Heinrich Klümper-Westkamp
Dr.-Ing. Juan Dong
M. Sc. Marian Skalecki Capes
88887.142484/2017
DFG ZO140/21-1
Working team
Slide 3
Introduction
The waste of Energy in Brazil in the last 3
years reached the amount of about EU 16.2
billion.
Brazil is appointed as the top country in
Energy waste in the Industry. Ovens and
boilers are the main responsible in the Industry
for the high amount of energy waste.
In Brazil, governmental programs as Inovar
Auto implemented a politics to force
companies to reduce vehicles fuel
consumption, installation of safety equipment.
Rota 2030 will also increase investment in
R&D and is being waited for next year.
As it is well known, development and
application of materials and processes to
achieve higher strength to weight ratios is
essential to decrease fuel consumption.
Source: Assoc. das Empresas de Serv. De Conservação de
Energia.
Motivation
Slide 4
Manufacturing routes for forged
automotive parts
Usually in the manufacturing of
automotive components a high
amount of energy is used in
the heating of the material for
hot forging or in the
conditioning of the material for
warm or cold forging.
Besides that the material has to
be heat treated to achieve the
desired mechanical properties,
what normally involves Q&T
with additional energy
consumption.
Finally, a surface treatment is
needed to improve the surface
related properties, as wear and
fatigue resistance.
Introduction
Slide 5
Introduction
Hot forging
Quenching or surface hardening
• Q&T
• Carburizing
• I.H.
Tempering
Machining
Aditional surface
treatment
• Nitriding.
• Nitrocarburizing
• Oxinitring
Typical Manufacturing Route in Hot-forging
Slide 6
T°T°Spheroidizing
• 30 hours
• Easier to Forge
Phosphatizing
Cold Forging• Improved
Mechanical Properties
Finish Machining
Gas Carburizing
• 8 hours
• Quenching
Tempering• 2 hours
• Error possibility of heat treatment
Introduction
Elevated amount of
energy necessary to
steel spheroidizing.
Typical Route in Cold Forging
Slide 8
New-generation bainitic steels
70
60
50
40
30
20
10
00 200 400 600 800 1000 12001400 1600
Yield Strength (MPa)
To
tal E
lon
ga
tio
n(%
)
Advanced Bainitic
Steels
0.2%C
0.3%C
MARTENSITIC
TRIP
DP, CP
HSLA
C-Mn
MILDBH
IF-HS
IF
Steel grade C[%] Mn[%] Si[%] Cr[%] YS [MPa] Rm [MPa] Strain[%]Research
Institute
20MnCrMo7 0,22 1,72 0,49 1,6 860 1250 14 EZM
HDB 0,17 1,52 1,46 1,32 782 1167 12,5 RWTH
Solam B1100
18MnCr5-3<0,2 <1,9 <1,5 >700 >1100 >15 Arcelor
Metasco MC
25MnCrSiVB60,25 1,3 0,9 0,8 >700 >1000 >15 Ascometal
H2/mod.
16MnCr50,16 1,25 800 1050 16 Hirschvogel
HSX 130HD 0,17 1,5 1,2 1,2 1030 1170 16,2 Swiss Steel
LUT–1
20MnCr50,20 1,3 0,5 1,1 850 1100 15 Uni Leoben
Slide 10
Objectives of the project
Development of process routes using continuous cooling bainitic steels aiming
at energy consumption reduction and improved mechanical and surface
properties for automotive and machine parts.
Determination of the processes window for some of the new continuous
cooling bainitic steels;
Detection (e.g. by Eddy-Current Analysis) of the ongoing phase
transformations during cooling from forging temperature;
Adjusting microstructure by thermomechanical processing;
Improvement of surface related properties (wear and friction) by developing
specific surface treatments.
Slide 11
Methodology
Materials of analysis:
Swiss Steel HSX 130;
A steel with a higher carbon
content;
A steel obtained by Spray
Forming process and/or by
carbon enrichment.
Swiss Steel HSX 130
C Mn Si Cr
0,17% 1,50% 1,20% 1,20%
(Bs) temperature reduction;
It promotes enrichment of austenite in
carbon during bainitic transformation;
It allows lower cooling rate on CCT diagram,
good for thermomechanical process.
Materials of analysis
Slide 12
Methodology
Route 1 - Forging above
austenitizing temperature with
different continuous cooling rates
until room temperature with
posterior cold forging process with
low deformation rates (calibration).
– Expected microstructure: Bainite +
martensite + low quantities of
retained austenite.
Tforging a, b, c: different cooling rates;R.T.: room temperature;
: forging;T inter.: intercritical temperature;
I : Calibration
Tinter.
Bs
Bf
I
T
t
a b c
R.T
Taust.
Thermomechanical process routes
Slide 13
Methodology
Route 2 – Forging above austenitizing temperature
(I) with posterior forging at intercritical temp. (II).
– Expected microstructure: Hardened ferrite +
retained austenite + martensite + bainite
(greater quantities).
Route 3 – Forging (I) with posterior warm forging in
the bainitic field (III).
– Expected microstructure: Retained austenite +
martensite + bainite (greater quantity).
Route 4 – Austenitizing and a single forging step in
the bainitic field (III).
– Expected microstructure: Bainite and retained
austenite.
Route 5 – Austenitizing and single forging at the
intercritical field (II).
– Expected microstructure: Hardened ferrite +
retained austenite + martensite + bainita.
I
II
III
Thermomechanical process routes
Slide 15
WP1 (a+b): Material acquisition and preparation of samples (IWT + UFRGS) – 11/17
to 01/18
WP2: Experimental simulation of thermo-mechanical process and in-process analysis
of microstructure (IWT) – 11/17 to 05/18
Material acquisition (IWT and UFRGS);
Manufacturing of the samples and preliminary heat treatment. (IWT and UFRGS);
Thermo-mechanical process with simplified sample geometry;
In-process microstructure control by eddy-current sensor technique;
Description of phase transformation kinetics and modeling;
Working packages
Methodology
Slide 16
X-ray diffraction experiments during
thermomechanical treatments for
evaluation of:
Phase transformations;
Crystallite size evolution;
Residual stresses;
Crystallographic texture;
Carbon content in solution based
on lattice parameter evolution;
WP3: Analysis of microstructure evolution via in-situ synchrotron XRD experiments
(IWT) – 04/18 to 11/18
Experimental device for thermomechanical treatments at European
Synchrotron Radiation Facility (Grenoble, France).
Methodology
Working packages
Slide 17
WP4: FEM Forging simulation (UFRGS) – 11/17 to 05/18
Finite element simulation;
Data crossing between simulation results, Gleeble data and thermodynamical simulations aiming to
plan thermo-mechanical treatments;
WP5: Determination of Heat Transfer Coefficients - HTC (IWT + UFRGS) – 12/17 to 04/18
Time-Temperature cooling curves acquisition;
Q-Probe;
Thermo-mechanical simulation;
Evaluation of boundary conditions for the heat transfer between die and workpiece;
Methodology
Working packages
Slide 18
Methodology
WP6: Thermo-mechanical Experiments (UFRGS + IWT) 04/18 to 11/18
Experimental forging in the different established routes;
Adaptation of Presses;
Manufacturing of Dies;
Instrumentation;
Development of cooling devices;
WP7: Mechanism-based definition of process window (IWT + UFRGS) – 02/18 to 01/19
Parameters definitions based on the previous results;
WP8: Post surface-strengthening treatments (IWT + UFRGS) – 10/18 to 11/19
Induction hardening;
Plasma Nitriding;
Deep Rolling;
Working packages
Slide 19
WP9: Experimental characterization of the treated samples (IWT + UFRGS) 01/18 to
04/19
WP10: Project management (UFRGS + IWT) – during all the project.
Metallographic analysis (MO & SEM);
X-Ray Diffraction;
Hardness tests;
Wear tests;
GDOES;
Compression and Tensile tests;
Fatigue tests;
Student exchange supervision;
On-line meetings;
National and international conferences;
Methodology
Working packages
Slide 20
Time schedule
Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May
IWT X X X X
UFRGS X X X X X
IWT
UFRGS
IWT X X X
UFRGS
IWT
UFRGS
IWT
UFRGS
IWT
UFRGS
IWT
UFRGS
IWT
UFRGS
IWT
UFRGS
IWT
UFRGS
WP9: Characterization tests.
WP5: Heat transfer coefficients.
WP6: Thermomechanical experiments.
WP8: Post superficial heat treatment.
WP10: Project management.
WP2: Experimental simulation of the
processes.
WP7: Definition of the window process.
WP1: Steel acquisition, confection and
sample characterization.
WP3: DRX experiments in-situ.
WP4: Forging simulation.
(2018 -2019)
Slide 21
Working plan for the extended period: 𝟑𝒓𝒅 and 𝟒𝒕𝒉
Steel production by Spray forming.
Carbon Enrichment of Samples.
Forging of real/model parts with
numerical simulation of the forging
process.
Mechanical testing of the produced
parts.
Final development of surface
treatments for the produced parts
and evaluation of wear and fatigue
properties.
Slide 22
Student missions
Study Missions 1th Trimester 2nd Trimester 3rd Trimester 4th Trimester5th
Trimester6th Trimester
7th
Trimester
8th
Trimester
Msc. Rodrigo Hatwig Eddy-Current analysis, Gleeble
Doctorate degree 2Route definition, steel
characterization
Eng.Tâmie Perozzo Dilatometry, XRD
Master Degree 2 Heat-transfer coefficient
Master Degree 3 Surface treatments
Graduation degree 1 Steel characterization
Graduation degree 2Thermomechanical
experiments
Graduation degree 3 Forged steel characterization
Post Doctoral
Microstructure
analysis during
thermomechanical
processing