International Conference on TRIP-Aided High Strength Ferrous Alloys

Editor: Prof. Bruno C. De Cooman

GRIPS' Sparkling World of Vol. 1: Proceedings Table of contents

Table of contents

De Cooman, Bruno C: 11 Preface

Bleck, Wolfgang: 13 Using the TRIP effect - the dawn of a promising group of cold formable Low and high alloy TRIP steels. Phase transformations. stability. Strainharden- ing. Temperature sensitivity. Strength- relationship. Energy absorption. Micro- structure optimization.

Fundamental Materials Science of the TRIP Phenomenon

Kruijver, Suzelotte; Zhao, Lie; Sietsma, Jilt; Offerman, Erik; van Dijk, Niels; Margulies, 25 Lawrence; Lauridsen, Erik; Grigull, Stephan; Poulsen, Henning; van derZwaag, Sybrand: In situ observations on the austenite stability in TRIP-steel during tensile testing TRIP steel. Synchrotron radiation. Austenite stability. Deformation. Diffraction. Carbon concentration. Austenite fraction. Crystal orientation.

lung, Thierry; Drillet, Jos&e; Couturier, Audrey; Olier, Christopher: 31 Detailed study of the transformation mechanisms in ferrous TRIP aided steels TRIP. Bainite transformation. Cementite composition. Austenite stability. Size effect

Furnemont, Quentin; Jacques, Pascal J.; Pardoen, Thomas; Lani, Frederic; Godet, 39 Stephane; Harlet, Philippe; Conlon, Kelly and Delannay, Francis. The macro- and micromechanics of TRIP-assisted multiphase steels, experiments and modelling TRIP-assisted multiphase steels. Multiphase microstructure. Nanohardness. Neutrons dif- fraction. Mechanical properties. Multi-scale approach. Modelling.

Sugimoto, Koh-ichi; Kikuchi, Ryo; Hashimoto, Shun-ichi: 45 Development of high strength low alloy TRIP-aided steels with annealed matrix Microstructure. Retained austenite. TRIP. Annealed martensite. Ductility. Formability. High strength steel

Allain, Sebastien; Chateau, Jean-Philippe; Bouaziz, Olivier: 51 Constitutive model of the TWIP effect in a polycrystalline high manganese content austenitic steel Steel. TWIP. Manganese. Modelling. Nucleation law. Twinning. Mean free path.

Vercammen, Steven; De Cooman, Bruno C; Akdut, Nuri; Blanpain, Bart; Wollants, Patrick: 55 Microstructural evolution and crystallographic texture formation of cold rolled aus- tenitic Fe-30Mn-3AI-3Si TWIP-steel Fe-Mn-AI-Si. Austenite. SFE. Cold rolling. Brass texture. Shear band.

Wirthl, Edwin; Pichler, Andreas; Angerer, Reinhold; Stiaszny, Peter; Hauzenberger, Karl; 61 Titovets, Yuri F.; Hackl, Michael: Determination of the volume amount of retained austenite and ferrite in small specimens by magnetic measurements TRIP-steel. Retained austenite. X-Ray diffraction.

Barb6, Liesbeth; De Meyer, Marijke; De Cooman, Bruno C: 65 Determination of the Mg temperature of dispersed phase TRIP-aided steels TRIP-aided steels. Mf temperature. Retained austenite. High strength steels. Martensitic transformation.

Int. Conf. on TRIP-Aided High Strength Ferrous Alloys Table of contents

Zhao, Lie; Tegus, Ojiyed; Bruck, Ekkes; van Dijk, Niels H.; Kruijver, Suzelotte; Sietsma, 71 Jilt; van derZwaag, Sybrand: Magnetic determination of the thermal stability of retained austenite in TRIP steel Retained austenite. Thermal stability. Martensite transformation. Thermo-magnetisation measurements. Thermodynamics. TRIP steel.

Allain, Sebastien; Chateau, Jean-Philippe; Bouaziz, Olivier; Legros, Marc; Garat, Xavier: 75 Characterization of the mechanical twinning microstructure in a high manganese content austenitic steel Steel. TWIP. Microtwins. Mean free path. Twinning kinetic. Acoustic emission.

Pychmintsev, Igor Y; Savrai, Roman A.; De Cooman, Bruno C: 79 Effect of stress state on the transformation behaviour and mechanical properties of TRIP-aided automotive steels CMnSi. CMnAISi. Cold rolled TRIP steel. Plasticity. High hydrostatic pressure. Transfor- mation behaviour. Microstructure.

Ros-Yanez, Tanya; Houbaert, Yvan; Petrov, Roumen; Mertens, Anne: 85 Characterisation of TRIP-assisted steel by atomic force microscopy and OIM TRIP-assisted steel. Atomic force microscopy. AFM. EBSD. OIM. Magnetic force micros- copy. MFM. Multiphase steel. Metallography. Phase identification.

Brux, Udo; Frommeyer, Georg; GrSssel, Oliver; Meyer, Lothar Werner; Weise, Andrea: 91 Development and characterization of high strength impact resistant Fe-Mn-(AI, Si) TRIP/TWIP steels Development of Fe-Mn-AI-Si alloys. Exploitation of TRIP effect and TWIP effect, y-e-a' phase transformation. Martensitic transformation. Twinning. Enhancement of formability by varied deformation parameters. Temperature. Strain rate.

Scott, Colin; Drillet, Josee: 97 Quantitative analysis of local carbon concentrations in TRIP steels Carbon concentration. Residual austenite. TEM. CBED. PEELS. Methodology.

TRIP-Aided Ferrous Alloys

Takahashi, Manabu; Yoshida, Hiroshi; Hiwatashi, Shinji: 103 Properties of TRIP typehigh strength steels TRIP. Crashworthiness. Retained austenite. Martensite transformation. Stretchability. Deep drawability. Bainite transformation.

Matsuda, Hiroshi; Kitano, Fusato; Hasegawa, Kohei; Urabe, Toshiaki; Hosoya,Yoshihiro: 113 Metallurgy of continuously annealed high strength TRIP steel sheet TRIP steel. Annealing conditions. Cooling conditions. Austempering conditions. Mechanical properties. Microstructure. Bainite. Retained austenite. Martensite. Carbon content.

Traint, Sandra; Pichler Andreas; Hauzenberger, Karl; Stiaszny Peter; Werner, Ewald: 121 Influence of silicon, aluminium, phosphorus and copper on the phase transforma- tions of low alloyed TRIP-steels Austenite transformation behaviour. Heat treatment. Retained austenite.

Jacques, Pascal J.; Harlet, Philippe; Delannay, Francis: 129 Critical assessment of the phase transformations occurring during the heat- treatment of TRIP-assisted multiphase steels TRIP-assisted multiphase steels. Hot-rolling. Mechanical properties. Multiphase micro- structures.

Int. Conf. on TRIP-Aided High Strength Ferrous Alloys Table of contents

Godet, Stephane; Harlet, Philippe; Delannay, Francis andJacques, Pascal J.: 135 Effect of hot-rolling conditions on the tensile properties of multiphase steels exhib- iting a TRIP effect TRIP-assisted multiphase steels. Hot-rolling. Mechanical properties. Multiphase micro- structures.

Zhao, Lie; Moreno, Juan; Kruijver, Suzelotte; Sietsma, Jilt; van derZwaag, Sybrand: 141 Influence of intercritical annealing temperature on phase transformations in a high aluminium TRIP steel Intercritical annealing. Thermodynamics. Dilatometry. X-ray diffraction. TRIP steel.

Barbe, Liesbeth; Tosal-Martfnez, Luc fa; De Cooman, Bruno C: 147 Effect of phosphorus on the properties of a cold rolled and intercritically annealed TRIP-aided steels High strength steels. Intercritical annealing. Retained austenite. Phosphorus.

Timokhina, liana B.; Hodgson, Peter D.; Pereloma, Elena V.: 153 Effect of alloying elements on the microstructure-property relationship in ther- momechanically processed C-Mn-Si TRIP steels Thermomechanical processing. Alloying elements. Granular bainite. Acicular ferrite. Re- tained austenite. Martensite. Morphology. Stability. Mechanical properties. Strain harden- ing coefficient.

Mahieu, Jan; Van Dooren, Danny; Barbe, Liesbeth; De Cooman, Bruno C: 159 Influence of Al, Si and P on the kinetics of intercritical annealing of TRIP-aided steels: thermodynamical prediction and experimental verification Transformation kinetics. Intercritical annealing. Silicon. Aluminum. Phosphorus.

Kim, Sung-Joon; Lee, Chang Gil; Jeong, Woo-Chang; Park, Ikmin: 165 Microstructures and mechanical properties of the 0.15% C TRIP-aided cold-rolled steels containing Cu, Ni and Cr TRIP. Multiphase steels. Tramp elements. Retained austenite. Tensile properties.

Pichler, Andreas; Traint, Sandra; Blaimschein, Martin; Sperl, Johann; Stiaszny, Peter; 171 Werner, EwaldA: Correlation between thermal treatment, retained austenite stability and mechanical properties of low-alloyed TRIP steels TRIP steel grades. Pearlite. Bainite. Martensite. Retained austenite. Overaging. Cooling rate. Transformation. Mechanical properties.

Timokhina, liana B.; Hodgson, Peter D.; Pereloma, Elena V.: 181 Effect of strain and morphology of the bainitic microstructure on the retained aus- tenite stability and mechanical properties of thermomechanically processed C-Mn- Si(-Nb) TRIP steels Thermomechanical processing. Granular bainite. Acicular ferrite. Retained austenite. Martensite. Morphology. Stability. Mechanical properties. Strain hardening coefficient.

Huang, Jin; Hammond, Robert P.; Conlon, Kelly; Poole, Warren J.: 187 An experimental study of the ferrite-austenite two phase region in a Fe-C-Mn-Si steel using neutron diffraction Multi-phase steel. Intercritical annealing. Neutron diffraction.

Van Hecke, Patrick; Penning, Jan: 193 TRIP-effects in austempered ductile irons Steel. TRIP-effect. Ductile iron. Austempering. Strength properties

Int. Conf. on TRIP-Aided High Strength Ferrous Alloys Table of contents

Ohlert, Joachim; Bleck, Wolfgang; Hulka, Klaus: 199 Control of microstructure in TRIP steels by niobium Phase transformations. Niobium. Volume ratio of bainite and ferrite. Carbon enrichment. Martensite nucleation. Process control. Mechanical properties.

Shi, Wen; Li, Lin; Zhou, Yuan; Fu, Ren Yu; Wei, Xi Cheng; De Cooman, Bruno C; Wol- 207 lants, Patrick; Zhu, Xiao Dong; Wang, Li: Effect of Mn content on the microstructures and mechanical properties of cold rolled O.15C-0.6Si-Mn TRIP steels TRIP steel. Microstructures. Mechanical properties.

Zhou, Yuan; Shi, Wen; Wei, Xi Cheng; Li, Lin; De Cooman, Bruno C; Wollants, Patrick; 211 Zhu, Xiao Dong; Wang, Li: Computer simulations of transformation during intercritical annealing in silicon- manganese TRIP steel Computer simulation. TRIP steel. Dictra. Phase transformation. Thermo-Calc. Thermody- namics.

Kestens, Leo; Petrov, Roumen; Houbaert, Yvan: 215 Orientation selective transformation during intercritical annealing of cold rolled TRIP steel TRIP-assisted steels. Recrystallization. Intercritical annealing. Selective transformation.

Petrov, Roumen; Kestens, Leo; Kaluba, Wlodzimierz; Houbaert, Yvan: 221 Recrystallization and austenite formation in a cold rolled TRIP steel during ultra fast heating Ultra fast heating. Recrystallization. Austenite formation. Cold rolled TRIP assisted steel.

Covarrubias, Octavio; Guerrero, Martha Patricia; Cola's, Rafael; Petrov, Roumen; Kestens, 227 Leo; Houbaert, Yvan: Transformation behaviour of Si and Mn bearing low carbon steels Heat treating. Carbon steels. Microstructure. Retained austenite.

Lucas, Aurelie; Herman, Jean-Claude; Schmitz, Alain: 231 Cu-containing TRIP steels TRIP steel. Copper. Retained austenite. Tramp elements, Scraps.

Physical Properties

Antretter, Thomas; Fischer, Franz Dieter; Tanaka Kikuaki; Cailletaud, Georges: 237 Theory, experiments and numerical modelling of phase transformations with em- phasis on TRIP Phase change. Transformation criterion. Interface jump condition. Dilatometric experi- ments. TRIP strain. Transformation kinetics. Finite element simulation. Backstress.

Moriau, Olivier; Tosal-Martfnez, Lucia; Verleysen, Patricia; Degrieck, Joris: 247 Dynamic mechanical properties of cold rolled TRIP steels for crash-relevant applica- tions Transformation induced plasticity. Strain rate sensitivity. Split Hopkinson bar tensile test. Energy absorption. Strain hardening.

Wei, Xi Cheng; Li, Lin; Fu, Ren Yu; De Cooman, Bruno C; Wollants, Patrick; Zhu, Xiao 253 Dong; Wang, Li: Time dependence of transformation process of Si-Mn TRIP steel during high-speed tensile impact testing Phase transformation. Time dependence. Strain rate. Impact tensile. TRIP steel.

8 Int. Conf. on TRIP-Aided High Strength Ferrous Alloys Table of contents

Van Rompaey, Tim; Furnemont, Quentin; Jacques, Pascal J.; Pardoen, Thomas; Blanpain, 259 Bart; Wollants, Patrick: Micromechanical modelling of TRIP-steels Low-alloyed TRIP steel. Thermodynamics. Micromechanics. Finite element modelling.

Yakubovsky, Oleg; Fonstein, Nina; Bhattacharya, Debanshu: 263 Stress-strain behaviour and bake hardenability of TRIP and TRIP-aided multiphase steels TRIP steels. Multiphase microstructure. Strain hardening. Baking hardening.

Fazeli, Fateh; Militzer, Matthias: 271 Towards an austenite decomposition model for TRIP steels Austenite decomposition kinetics. Continuous cooling. Ferrite. Bainite. Diffusion. Solute drag.

Vasilakos, Apostolos N; Ohlert, Joachim; Giasla, Katerina; Haidemenopoulos, Gregory N.; 277 Bleck, Wolfgang: Low-alloy TRIP steels: a correlation between mechanical properties and the retained austenite stability Low alloy TRIP steels. Retained austenite stability. TRIP effect.

Jacques, Pascal J.; Petein, Arnaud; Harlet, Philippe: 281 Improvement of mechanical properties through concurrent deformation and trans- formation: new steels for the 21st century TRIP-assisted multiphase steels. Fe-Mn alloys. TRIP effect. Mechanical properties. Dislo- cation strengthening. Martensitic transformation.

Fu, Ren Yu; Wei, Xi Cheng; Shi, Wen; Li, Lin; De Cooman, Bruno C; Wollants, Patrick; 287 Zhu, Xiao Dong; Wang, Li: Dynamic tensile characteristic of high strength low alloy TRIP steel and its model- ling Dynamic tensile. TRIP. Strain rate. Mechanical property. Modelling.

Mertens, Anne; Jacques, Pascal; Harlet, Philippe; Delannay, Francis: 293 On the optimisation of the mechanical properties of two aluminium-alloyed multi- phase TRIP-assisted steels Aluminium-alloyed TRIP-assisted steels. Heat treatment. Microstructures. Mechanical properties.

Pychmintsev, Igor Y; Savrai, Roman A.; De Cooman, Bruno C; Moriau, Olivier: 299 High strain rate behaviour of TRIP-aided automotive steels CMnSi, CMnAISi, Plasticity, Specific energy, Transformation behaviour, Microstructure change, Adiabatic heating.

Baik, Seung Chul; Park, Sung Ho; Kwon, Ohjoon; Kim, Dong-Ik, Oh, Kyu Hwan: 303 Effects of nitrogen on the mechanical properties of cold rolled TRIP steel sheets TRIP steels. Tensile tests. N addition. Mechanical properties. Austempering. Precipitation. AIN precipitates. Retained austenite. Ferrite and bainte grain size.

Tosal-Martinez, Lucia; Jacobs, Sigrid; Claessens, Serge; Vandeputte, Sven: 311 Influence of microstructure, strain hardening behaviour and stress state on the formability of cold rolled TRIP steels Phase fractions. Morphology and distribution. Strain hardening behaviour. Formability. Forming Limit Diagram.

Zou, Hong Hui; Li, Lin; Fu, Ren Yu; De Cooman, Bruno C; Wollants; Patrick; Zhu, Xiao 317 Dong, Wang, Li: Effect of retained austenite stability of Si-Mn TRIP steel on the product of strength and ductility Retained austenite. TRIP-assisted steel. Tensile. Ductility. Elongation rate. Fracture mechanism.

Int. Conf. on TRIP-Aided High Strength Ferrous Alloys Table of contents

Automotive Applications

Godereaux, Stephane; Vivet, Sabine; Beaudoin, Jean-Frangois: 321 Application of TRIP steels in the automotive industry Formability. Stamping. Bake hardening. Fatigue. Crash. Assembling. Work hardening.

Greisert, Carsten; Wesemann, Jurgen: 327 Influence of constant and variable restraining force on springback of TRIP700 and stainless steel grades High strength steel. Stainless steel. Springback. Shape set. Duncan Shabel test.

Foct, Jacques; Stolarz, Jacques; Baffle, Natacha; Massol, Karen; Vogt, Jean-Bernard: 333 Fatigue induced phase transformation in ferrous alloys Martensitic transformation. Stainless steels. Fatigue. Short cracks. Crack propagation. Md temperature.

Papaefthymiou, Spyros; Bleck, Wolfgang; Kruijver, Suzelotte; Zhao, Lie; Sietsma, Jilt; van 341 der Zwaag.Sybrand: Microstructure development and mechanical behaviour of Al-containing TRIP-steels Phase transformations. Microstructure. Deformation. Dilatometry. Mechanical properties.

Doege, Eckart; Kulp, Steffen; Sunderkotter, Christina: 347 Properties and application of TRIP-steel in sheet metal forming Deep drawing. TRIP-steel. Springback. Dent resistance. Tribology. Young's modulus. Forming limit curve.

Cretteur, Laurent; Koruk, Ali-lhsan; Tosal-Martfnez, Lucia: 353 Improvement of weldability of TRIP steels by use of in-situ pre- and post-heat treat- ments TRIP steel. Spot welding. Heat treatments. Design of experiment. Process parameters. Mechanical properties.

Streicher, Amy M.; Speer, John G.;. Matlock, David K.: 359 Forming response of retained austenite in a C-Si-Mn high strength TRIP sheet steel TRIP. Sheet steel. Retained austenite. Martensite. Forming. Uniaxial tension. Biaxial stretching.

Xu Luoping; Li Lin; Wei Xi Cheng; Fu Ren Yu; Cooman B.C.De; Wollants Patrick; Wang Li; 367 Zhu Xiao Dong: Effect of surface treatment on dynamic mechanical properties of high strength low alloy Si-Mn TRIP steel Phosphatisation. Zn electroplating. TRIP steel. Dynamic property. Strain rate.

Wei Xi Cheng, Li Lin, Fu Ren Yu, Cooman B. C. De, Wollants Patrick, Wang Li, Zhu Xiao 373 Dong: Influence of strain rate on strain-induced transformation of retained austenite to martensite in high strength low alloy TRIP steels Strain rate. TRIP steel. Retained austenite. SEM. Dynamic behavior.

Mintz, Barrie: 379 The influence of aluminium on the strength and impact properties of steel TRIP. Strength. Impact behaviour. Aluminium. Martensite.

Index of authors 383

10 Int. Conf. on TRIP-Aided High Strength Ferrous Alloys