scholarly journals The Integration of Process and Product Metallurgy in Niobium Bearing Steels

Metals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 671 ◽  
Author(s):  
Steven Jansto
Keyword(s):  
Grain Refinement ◽  
Hot Rolling ◽  
Value Added ◽  
High Strength ◽  
Success Factor ◽  
Physical Metallurgy ◽  
Market Demand ◽  
Production Scale ◽  
Process Metallurgy ◽  
Steel Grades

A review of the technological integration of both the process and physical metallurgical advancements of value-added niobium (Nb) microalloyed thermo-mechanical controlled process (TMCP) steels have evolved into the development of higher quality steels for more demanding end user requirements. The connection of process and physical metallurgy is evolving through the integration of research that is aimed at improving product quality. However, often the connection of the process metallurgical parameters is not reported, especially with industrial data. The importance of this innovative metallurgical connection is validated by the market demand for reduced fuel consumption, improved quality, and CO2 emissions in both the automotive and construction sectors. This situation has further increased the demand for new higher quality Nb-bearing steel grades. This integrative process/physical metallurgical (IP/PM) approach applies to both low and high strength steel grades in numerous applications. Often, the transition from laboratory melted and TMCP to the production scale is challenging. The methodology, process control, and key production steps that are required during the melting, ladle metallurgy, continuous casting, thermal, and hot rolling production conditions often vary significantly from the laboratory conditions. Understanding the reasons and corrective action for these variations is a critical product development success factor. These process metallurgy parameters for the industrial melting, casting, reheating, and hot rolling of Nb grades are connected and correlated to the resultant microstructures, physical metallurgy, and mechanical properties. These advanced high strength steels are microalloyed with Nb, V, Ti and/or other elements, which affect the austenite-ferrite transformation. Niobium enables the achievement of substantial grain refinement when the plate or sheet is rolled with the proper reheat, hot reduction, and thermal schedule. A recently developed key metallurgical transition is in progress applying this integrative approach with the use of MicroNiobium. A reduction of Mn and C levels with the complementary refinement of the microstructural grain size through MicroNiobium additions improves the robustness of the steel to better accommodate some process metallurgy variations. Applications are evolving in lower strength steels with Nb to achieve complementary grain refinement.

High Quality TMCP Production and Metallurgy of Niobium Bearing Steels

2016 ◽  
Vol 879 ◽  
pp. 820-825
Author(s):  
Steven G. Jansto
Keyword(s):  
Mechanical Properties ◽  
Continuous Casting ◽  
High Strength Steels ◽  
Value Added ◽  
Bearing Steel ◽  
Carbon Equivalent ◽  
Chemical Compositions ◽  
Market Demand ◽  
Production Scale ◽  
Lower Carbon

The technological and metallurgical advancements of value-added niobium (Nb) microalloyed thermo-mechanical controlled process (TMCP) plate steels continue to be developed for more demanding end user requirements. The market demand for reduced fuel consumption and CO2 emissions in the automotive and construction sectors have further increased the demand for these new and advanced higher quality Nb-bearing steel grades. Often, the transition from laboratory melted and TMCP hot rolled heats to the production scale requires some continuous casting, thermal and mechanical metallurgy adjustments from the laboratory results in order to accomplish proper industrial continuous casting and hot rolling processes. These advanced high strength steels are microalloyed with Nb, Mo and/or other elements which affect the austenite-ferrite transformation. Niobium enables achievement of substantial grain refinement when the plate is rolled with the proper reduction and thermal schedule. The effects of these microalloying elements on the continuous cooling transformation behavior must be carefully controlled during the reheating and rolling process to successfully achieve the desired mechanical properties. TMCP applications have been successfully developed in numerous product sectors with thickness exceeding 120 mm. Since the very fine grained microstructure improves toughness and increases the yield strength, this TMCP process enables the required tensile properties with the growing trend to leaner chemical composition designs (less than 0.10%C) and excellent toughness properties. The consequence of leaner chemical compositions, especially lower carbon content and lower carbon equivalent enhances mechanical properties, fabrication and weldability.

The Role of Niobium in Lightweight Vehicle Construction

2007 ◽  
Vol 537-538 ◽  
pp. 679-686 ◽  
Author(s):  
Hardy Mohrbacher ◽  
Christian Klinkenberg
Keyword(s):  
Grain Refinement ◽  
High Strength Steel ◽  
Mechanical Performance ◽  
High Strength Steels ◽  
High Strength ◽  
Interstitial Free ◽  
Niobium Microalloying ◽  
Hsla Steels ◽  
Steel Grades ◽  
Different Characteristics

Modern vehicle bodies make intensive use of high strength steel grades to improve the weight and the mechanical performance simultaneously. A broad range of medium and extra high strength steel grades is available. These steel grades have different characteristics concerning strength, formability and weldability. For many steel grades microalloying by niobium is the key to achieve their characteristic property profile. In HSLA steels niobium enhances the strength primarily by grain refinement. In interstitial free high strength steels niobium serves as a stabilizing element and also assists in obtaining the bake hardening effect. Some modern multiphase steels rely on niobium to achieve additional strength via grain refinement and precipitation hardening. Microstructural control provides a way to further optimize properties relevant to automotive processing such as cutting, forming and welding. The relevance of niobium microalloying in that respect will be outlined.

scholarly journals STUDY ON MECHANICAL PROPERTIES AND MICROSTRUCTURE OF 42CrMo4/NANOS-BA® HIGH-STRENGTH CLAD PLATES AFTER THE PROCESS OF HOT ROLLING AND TWO-STAGE HEAT TREATMENT WITH ISOTHERMAL TRANSFORMATION

2021 ◽  
Vol 73 (1) ◽  
pp. 22-31
Author(s):  
Bartłomiej WALNIK ◽  
Dariusz Woźniak ◽  
Aleksandra NIESZPOREK ◽  
Mariusz ADAMCZYK
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Hot Rolling ◽  
High Strength ◽  
Isothermal Transformation ◽  
Two Stage ◽  
Physical Experiments ◽  
Microstructure Examination ◽  
Steel Grades ◽  
Stage Heat Treatment

The aim of the study was to develop a technology for welding non-weldable 42CrMo4 and NANOS-BA® steel grades in the process of hot rolling and two-stage heat treatment. As a result of physical experiments carried out in a line for semi-industrial simulation of the production of metals and their alloys (LPS) and additional heat treatment, a durable combination of 42CrMo4 and NANOS-BA® steels with high mechanical properties was obtained, including: Rp0.2 = 1036 MPa, Rm = 1504 MPa and A = 10.9%, without microscopically visible cracks and other discontinuities in the joined surface. The quality of the 42CrMo4/NANOS-BA® clad plates produced in this way was assessed on the basis of microstructure examination as well as bending, shear and tensile strength tests.

Rosenhain Centenary Conference - 3. Materials development present and future 3.5 A forward look at some steel developments based on physical metallurgy

1976 ◽  
Vol 282 (1307) ◽  
pp. 329-339
Keyword(s):  
Steel Industry ◽  
Materials Science ◽  
High Strength Steels ◽  
High Strength ◽  
Short Review ◽  
Physical Metallurgy ◽  
Social Environments ◽  
Materials Development ◽  
Materials Engineering ◽  
Process Metallurgy

It is projected that research on the physical metallurgy of steel during the next decade will be directed towards translating the impressive gains in our understanding of materials science into materials engineering. This will require the physical metallurgist to have an awareness of the economic and social environments in which the steel industry operates, the nature and special problems of technology transfer in the industry and the interdependencies of physical, chemical and process metallurgy. These points are illustrated by brief discussions of some areas of materials science of direct interest in the physical metallurgy of steel, some expected developments in low-alloy and in high-strength steels, and by a short review of a few of the more important problems awaiting practical solutions.

Effects of Cooling Rate on Microstructure and Properties of Nb-Ti Micro-Alloyed Steel

2013 ◽  
Vol 341-342 ◽  
pp. 208-212
Author(s):  
Xin Li ◽  
Jie Zhao ◽  
Xun Yang ◽  
Jun Cheng Bao ◽  
Bao Qun Ning
Keyword(s):  
Mechanical Property ◽  
Cooling Rate ◽  
Grain Refinement ◽  
Hot Rolling ◽  
High Strength Steel ◽  
High Strength ◽  
Alloyed Steel ◽  
Continuous Cooling Transformation ◽  
Micro Alloyed Steel ◽  
P Colonies

Continuous cooling transformation (CCT) curves of deformed austenite (A) of Nb-Ti microalloying high strength steel were measured using Gleeble-3800 thermo-mechanical simulator, and corresponding transformation and structure were analyzed, and the effects of cooling rate on the tested steels mechanical property were studied. The resultes showed that the Ar3transformation point decreased with increasing cooling rate after hot-rolling. The morphology of ferrite (F) grains changed from polygonal to lath, and the pearlite (P) colonies became more fine with increasing cooling rate. The quantity of ferrite and pearlite decreased, and the quantity of bainite (B) and martensite (M) increased. Then the hardness of Nb-Ti micro-alloyed steel is increased along with the increasing cooling rate, which may owing to the reasons that the hardness of ferrite and pearlite is far smaller than that of bainite and martensite, and the grain refinement causes the hardness increasing.

scholarly journals Arvedi ESP Technology - The Hot Rolling of HS and AHS Thin Gauge Steel Strips

2016 ◽  
Vol 854 ◽  
pp. 42-47 ◽  
Author(s):  
Roberto Venturini ◽  
Paolo Daniele Avancini ◽  
Nicola Barbier ◽  
Alessandro Rizzi
Keyword(s):  
Hot Rolling ◽  
Industrial Production ◽  
High Strength Steels ◽  
High Strength ◽  
Dual Phase ◽  
Advanced High Strength Steels ◽  
Steel Strips ◽  
Start Up ◽  
Steel Grades ◽  
Mechanical Investigation

After 5 years from start-up, Arvedi ESP Technology has achieved outstanding performances in terms of production, products and quality. The technology has proved particularly suitable for the production of thin gauge strips (< 2 mm). This paper presents the experiences in the production of high strength and advanced high strength steels, such as micro-alloyed S550MC, dual phase DP600 and ferritic bainitic HR60 in thin gauge strips on the ESP line of Acciaieria Arvedi S.p.A. in Cremona. Some aspects of the industrial production process for these steel grades are highlighted on the basis of casting and rolling parameters and microstructural and mechanical investigation.

3rd Generation AHSS by Thin Slab Technology

2018 ◽  
Vol 941 ◽  
pp. 627-632 ◽  
Author(s):  
Christian Klinkenberg ◽  
Akhil Varghese ◽  
Christoph Heering ◽  
Olga Lamukhina ◽  
Uwe Grafe ◽  
...  
Keyword(s):  
Hot Rolling ◽  
High Strength ◽  
Hot Forming ◽  
Thin Slab ◽  
Complex Phase ◽  
Steel Making ◽  
Steel Grades ◽  
Mn Content ◽  
Si Content ◽  
Few Data

Modern steel making and hot rolling processes like CSP® thin slab technology require precise data on casting and rolling behavior of the produced steel grades. Up today only few data is available for the latest generations of advanced high strength steel (AHSS) grades. AHSS have developed by 3 generations [1, 2]. 1st Generation AHSS as dual phase (DP), complex phase (CP), martensitic (MS) and transformation induced plasticity (TRIP) steel grades are currently applied in automotive industry. 2nd and 3rd Generation AHSS typically have elevated Mn-content as well as Al and Si content. High Mn-content of up to 30% seriously affects casting and forming properties of 2nd Generation AHSS. In particular, the large solidification range of more than 100 K prevents commercial production of these steel grades by continuous casting [3]. 3rd Generation AHSS with reduced Mn-content up to about 12% are currently under development [1-4]. Investigations have been carried out to assess the CSP® thin slab process for the production of such grades. To this purpose solidification and hot forming properties of different alloys having Mn-content up to 10% have been examined by thermodynamic calculations and laboratory testing by hot forming dilatometry. The achieved flow curves match figures achieved on a hot rolling mill.

The Nature of Delta Phase Precipitation in Inconel 718

1982 ◽  
Vol 40 ◽  
pp. 724-725
Author(s):  
L. S. Lin ◽  
C. C. Law
Keyword(s):  
Inconel 718 ◽  
Base Alloy ◽  
High Strength ◽  
Physical Metallurgy ◽  
Nickel Base Alloy ◽  
Phase Precipitation ◽  
Weight Percentage ◽  
Delta Phase ◽  
The Subject ◽  
Nickel Base

Inconel 718, a precipitation hardenable nickel-base alloy, is a versatile high strength, weldable wrought alloy that is used in the gas turbine industry for components operated at temperatures up to about 1300°F. The nominal chemical composition is 0.6A1-0.9Ti-19.OCr-18.0Fe-3Mo-5.2(Cb + Ta)- 0.1C with the balance Ni (in weight percentage). The physical metallurgy of IN 718 has been the subject of a number of investigations and it is now established that hardening is due, primarily, to the formation of metastable, disc-shaped γ" an ordered body-centered tetragonal structure (DO2 2 type superlattice).

Mechanical Properties and Aging Behavior of Ultrafine Grained Al-Ag Alloy Fabricated by Accumulative Roll-Bonding

2014 ◽  
Vol 794-796 ◽  
pp. 851-856
Author(s):  
Tadashiege Nagae ◽  
Nobuhiro Tsuji ◽  
Daisuke Terada
Keyword(s):  
Mechanical Properties ◽  
Grain Refinement ◽  
Accumulative Roll Bonding ◽  
Precipitation Hardening ◽  
Tensile Elongation ◽  
Solution Treatment ◽  
High Strength ◽  
Subsequent Aging ◽  
Roll Bonding ◽  
Ultrafine Grained

Accumulative roll-bonding (ARB) process is one of the severe plastic deformation processes for fabricating ultrafine grained materials that exhibit high strength. In aluminum alloys, aging heat treatment has been an important process for hardening materials. In order to achieve good mechanical properties through the combination of grain refinement hardening and precipitation hardening, an Al-4.2wt%Ag binary alloy was used in the present study. After a solution treatment at 550°C for 1.5hr, the alloy was severely deformed by the ARB process at room temperature (RT) up to 6 cycles (equivalent strain of 4.8). The specimens ARB-processed by various cycles (various strains) were subsequently aged at 100, 150, 200, 250°C, and RT. The hardness of the solution treated (ST) specimen increased by aging. On the other hand, hardness of the ARB processed specimen decreased after aging at high temperatures such as 250°C. This was probably due to coarsening of precipitates or/and matrix grains. The specimen aged at lower temperature showed higher hardness. The maximum harnesses achieved by aging for the ST specimen, the specimens ARB processed by 2 cycles, 4 cycles and 6 cycles were 55HV, 71HV, 69HV and 65HV, respectively. By tensile tests it was shown that the strength increased by the ARB process though the elongation decreased significantly. However, it was found that the tensile elongation of the ARB processed specimens was improved by aging without sacrificing the strength. The results suggest that the Al-Ag alloy having large elongation as well as high strength can be realized by the combination of the ARB process for grain refinement and the subsequent aging for precipitation hardening.

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