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 7

Introduction

Conventional Quenching and

Austempering

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 9

New-generation bainitic steels

Si

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 14

Methodology

Surface Modification

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

Slide 23

Thank you for your attention!

We would like to acknowledge the German Research Council (DFG) and

CAPES for funding of the projects Capes 88887.142484/2017 and DFG

ZO140/21-1