Course Outline
1. Introduction – Fundamentals: Microstructure-Properties Relationships in Steel Products
Lattice Strength
a. Structure of glide in ferrite and austenite
b. Homogeneous shear
c. Dislocations and the Peierls barrier
d. Double kink mechanism in ferrite
e. The critical resolved shear stress, the Schmid factor
f. Strength of ferrite
g. Effect of the strain rate
h. Effect of the temperature
2. Solid Solution Hardening
a. The structure of solid solutions
b. Local effects of solute atoms on the lattice
c. Empirical approach to solid solution hardening
d. Theory of solid solution hardening
e. Solid solution softening
3. Grain Size Strengthening
a. What is grain size?
b. The Hall-Petch equation
c. Theories of grain size strengthening
d. Grain size reduction: CRC versus TMCP
e. Effect of interstitials
f. Block size effects in martensite
4. Strain Hardening
a. Strain hardening as an Engineering Material Parameter
b. Difference in the strain hardening in ferrite and austenite
c. Dislocation cell formation
d. Theories of strain hardening
e. The Hirsch-Bailey equation
f. Dislocation density evolution dependent strain hardening
5. Precipitation Hardening
a. Particle cutting versus particle by-passing
b. Examples of precipitation hardening particles in steels
c. Fundamentals of precipitation hardening: size and volume fraction effects
d. Cu-precipitation hardening
e. The Orowan-Gladman equation for micro-alloying
f. Example: Vanadium micro-alloying of an austenitic steel
6. Micro Structure Hardening
a. Strength-Ductility balance of standard steel grades
b. Current requirements evolutions for structural steel products
c. Plasticity-enhancing mechanisms in AHSS and UHSS grades
d. Multi-phase steels as composite materials
e. Examples: CMn structural steel and duplex stainless steels
f. Backstresses and the Bauschinger effect
7. Bake-Hardening (BH) Steel
a. Interstitials in steel
b. Technical considerations: paint baking in the car industry
c. Technical considerations: prevention of nicks and dents
d. Static strain aging by solute C and/or N
e. Conditions for strain localization in steel
f. The breakaway stress
g. Production methods for BH steel
h. Comparison of the BH effect in LC and ULC steel
i. Measuring the BH response of ULC steel
j. Limitation to the BH effect in ULC steel
8. Dual Phase (DP) Steel
a. DP steel grade specifications
b. Composition of DP steel
c. HSM Processing of DP steel
d. CR and intercritically annealed DP steel
e. Mechanical properties of DP steel
f. BH response of DP steel
9. Transformation-Induced Plasticity (TRIP) Steel
a. TRIP effect in meta-stable austenitic stainless steel
b. Principle of multi-phase low C TRIP steel
c. The Ms, Mss, Md, Md30 temperatures
d. Stress and strain induced martensite transformation
e. Transformation kinetics
f. TRIP steel microstructure: C partitioning
g. TRIP Steel processing
h. Mechanical properties of the constituent phases in TRIP steel
i. High strain rate properties
j. Bake-hardening response of TRIP steel
10. Ferrite-Bainite (FB) and Complex Phase (CP) Steel
a. FB and CP steel grade specifications
b. Stretch flanging, hole expansion performance of AHSS and UHSS
c. The hole expansion test
d. Bainite morphology
e. Hot rolled bainitic steel: effect of the coiling on the properties
11. Press-Hardening Steel (PHS)
a. The reason for the success of press hardening steel
b. The press hardening processes
c. Mechanical properties of press hardening steel
d. Aluminized press hardening steel
e. Galvanized press hardening steel
f. Coating degradation issues
12. Quench and Partitioning (Q&P) Processing
a. Drivers for formable UHSS grades developments
b. Fundamentals of the Quench and Partitioning processing methods
c. Influence of the main Q&P processing parameters
d. Technical considerations
e. Understanding the mechanical properties of Q&P steel
13. Thin Slab Direct Rolling (TSDR) Processing
a. Drivers for TSDR technology developments.
b. Fundamental materials processing aspects in TSDR.
c. Influence of the main TSDR process parameters.
d. Technical and metallurgical aspects of the TSDR process.
e. Application examples:
1. Influence of tramp elements.
2. Effect of Ti micro-alloying additions.
4. TSDR as a PHS production route.
14. Practical exercise: DP 600 Steel Design
a. Selection of the DP steel grade specification
b. Modeling DP steel properties
c. Selection of the composition of DP steel
d. HSM processing parameters of DP steel
e. CR and intercritically annealing parameters of DP steel
f. Industry test
g. Evaluation of the mechanical properties of DP steel