Influence of Chromium on the Hall-Petch Coefficient in Ferritic Steel

2012 ◽  
Vol 706-709 ◽  
pp. 2130-2133 ◽  
Author(s):  
Akira Hironaka ◽  
Nobuo Nakada ◽  
Toshihiro Tsuchiyama ◽  
Setsuo Takaki
Keyword(s):  
Stainless Steels ◽  
Strengthening Mechanism ◽  
Interstitial Free ◽  
Ferritic Stainless Steels ◽  
Carbon And Nitrogen ◽  
Solid Solution Strengthening ◽  
Good Corrosion Resistance ◽  
Solution Strengthening ◽  
C And N ◽  
Grain Refinement Strengthening

In ferritic stainless steels, the amount of Cr is moderately controlled to have good corrosion resistance in applied environment. However, it also affects the yield strength of ferritic stainless steels through solid solution strengthening and grain refinement strengthening. Until now, some researches have been performed using commercial stainless steels but the obtained results contain the effect of solute interstitials (C and N). In this paper, the influence of Cr on the above both strengthening mechanism was discussed by using interstitial free ferritic stainless steel in which carbon and nitrogen are completely fixed as Ti(C,N). A previous paper has reported that the addition of chromium gives different influences to the Hall-Petch coefficient depending on the amount of Cr. However, our research has reveals the fact that the change of Hall-Petch coefficient is not due to the effect of chromium but due to small amount of carbon which exists as an impurity in ferritic stainless steels. It was concluded that chromium itself does not give any influence to the Hall-Petch coefficient of ferritic iron.

Effect of Reactive Elements and Microstructure of Steel on High Temperature Oxidation Behaviour of Ferritic Stainless Steels

2010 ◽  
Vol 297-301 ◽  
pp. 1354-1361
Author(s):  
Hisao Fujikawa
Keyword(s):  
Stainless Steels ◽  
Diffusion Rate ◽  
Austenite Phase ◽  
Oxidation Behaviour ◽  
Temperature Oxidation ◽  
Ferritic Stainless Steels ◽  
Transmission Electron ◽  
Oxidation Performance ◽  
C And N ◽  
Stabilizing Element

The effect of different carbonitride forming elements on the oxidation performance of a 17Cr steel has been investigated. Whilst C and N are shown to have deleterious effects on the formation of protective oxides on unstabilised steel, a relationship has been found between the strength of the carbonitride former and the relative improvement in the oxidation performance. Furthermore, the appearance of the austenite phase has harmful influence on the oxidation resistance of the ferritic steel because the diffusion rate of Cr, Fe and so on is much slower in the austenitic structure than in the ferritic structure. The improvement is the most pronounced when the stabilizing element is Zr. The formation of the scale observed using transmission electron microscopy has been shown to be strongly controlled by the inward diffusion of the oxidant.

The Grain Refining and Strengthening Mechanism of C-Mn Steel by CSP

2011 ◽  
Vol 261-263 ◽  
pp. 712-716 ◽  
Author(s):  
Chao Zhang ◽  
Run Wu ◽  
Chang Song ◽  
Yong Fu Zhang ◽  
Shu Li Li ◽  
...  
Keyword(s):  
Strengthening Mechanism ◽  
Rolling Process ◽  
Precipitation Strengthening ◽  
Physical Metallurgy ◽  
Grain Refining ◽  
Strengthening Mechanisms ◽  
Solution Strengthening ◽  
Dislocation Strengthening ◽  
Mn Steel ◽  
Grain Refinement Strengthening

The grain refining of C-Mn steel on CSP line was investigated in this paper. The grain size was about 100μm after rolling by stand F1 and then decreased all the way of the rolling process(stands F2-F6) to 15μm. The strengthening mechanisms, grain refinement strengthening, solution strengthening, precipitation strengthening and dislocation strengthening, were figured out to develop a physical metallurgy model for prediction of the properties. It was noted that there is an agreement between the predicted properties and the measured ones of the steel.

scholarly journals Effects of Graphene Nanoplates on the Mechanical Behavior and Strengthening Mechanism of 7075Al Alloy

Materials ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 5808
Author(s):  
Jinfeng Leng ◽  
Yunfan Dong ◽  
Binghui Ren ◽  
Ran Wang ◽  
Xinying Teng
Keyword(s):  
Uniform Elongation ◽  
High Strength ◽  
Strengthening Mechanism ◽  
Solid Solution Strengthening ◽  
High Toughness ◽  
Solution Strengthening ◽  
Dislocation Strengthening ◽  
Increased Strength ◽  
7075Al Alloy ◽  
Graphene Nanoplates

7075Al alloy is the preferred material for lightweight automotive applications, but the existing problem is that it is difficult to combine high strength and high toughness. This paper presents our research aimed at obtaining high strength and high toughness materials by adding a nano-phase to realize microstructure refinement. Graphene nanoplates (GNP)/7075Al composites and 7075Al alloy were prepared by a stirring casting method in the present study. In comparison to 7075Al, the tensile strength of GNP/7075Al composites was increased from 572 MPa to 632 MPa while maintaining good uniform elongation of 8% to 10%. The increased strength behavior of GNP/7075Al composites while maintaining the plasticity is discussed in terms of grain refinement and dislocation evolution by analyzing the composite microstructure and quantitatively analyzing the contributions of grain boundary strengthening, solid solution strengthening, precipitation strengthening and dislocation strengthening. GNP’s strengthening of GNP/7075Al composites is mainly attributed to the refinement of grain size and the increase of dislocation density.

Microstructure and Strengthening Mechanism of Natural Aging of TZS88 Aluminum Alloy

2012 ◽  
Vol 476-478 ◽  
pp. 59-64
Author(s):  
Chong Cai Zhang ◽  
Yong Fei Yang ◽  
Wei Xing Wu ◽  
Long Wang
Keyword(s):  
Solid Solution ◽  
Aluminum Alloy ◽  
Natural Aging ◽  
Strengthening Mechanism ◽  
Dispersion Strengthening ◽  
Solid Solution Strengthening ◽  
Solution Strengthening ◽  
Solid Solution Matrix ◽  
Solution Matrix ◽  
Scanning Electron

In this paper, TZS88 aluminum alloy mechanical properties of three months of natural aging is tested, the microstructure and the strengthening mechanism is studied by the application of optical metallographic microscope and scanning electron microscopy. The results show that TZS88 aluminum reinforced mainly caused by solid solution strengthening, aging strengthening and dispersion strengthening, and as such its tensile strength, hardness and elongation in the natural aging have reached ZQSn6-6-3 bronze level, the microstructure are compounds which included α(Al) solid solution matrix + Sn + s, θ, T, ε etc.

ARMCO 430

Alloy Digest ◽  
2000 ◽  
Vol 49 (9) ◽  
Keyword(s):  
Mechanical Properties ◽  
Corrosion Resistance ◽  
Physical Properties ◽  
Tensile Properties ◽  
Oxidation Resistance ◽  
Stainless Steels ◽  
Heat Treating ◽  
Ferritic Stainless Steels ◽  
Good Corrosion Resistance

Abstract Armco Type 430 is one of the most widely used of the “nonhardenable” ferritic stainless steels. It combines good corrosion resistance and heat and oxidation resistance up to 816 deg C (1500 deg F) with good mechanical properties. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, and joining. Filing Code: SS-803. Producer or source: AK Steel Inc.

Influence of Carbon Reinforcements on the Mechanical Properties of Ti Composites via Powder Metallurgy and Hot Extrusion

2013 ◽  
Vol 750 ◽  
pp. 40-43 ◽  
Author(s):  
Shu Feng Li ◽  
Bin Sun ◽  
Katsuyoshi Kondoh ◽  
Takanori Mimoto ◽  
Hisashi Imai
Keyword(s):  
Mechanical Properties ◽  
Powder Metallurgy ◽  
Carbon Nanofiber ◽  
Hot Extrusion ◽  
Strengthening Mechanism ◽  
Matrix Composites ◽  
Solid Solution Strengthening ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Solution Strengthening

Ti metal matrix composites (Ti–MMCs) reinforced by vapor grown carbon nanofiber (VGCF) and graphite particle (Gr) were prepared via powder metallurgy and hot extrusion. Ti with 0~0.4wt% VGCF/Gr mixture powders were consolidated by using spark plasma sintering (SPS) at 800 °C. Hot extrusion was then performed at 1000 °C with an extrusion ratio of 37:1. Microstructures and mechanical properties of the as-extruded Ti composites were investigated. Tensile strength of Ti–VGCF/Gr composites was steadily augmented when additions of VGCF/Gr were increased from 0.1 to 0.4 wt%. YS and UTS were increased 40.2% and 11.4% for Ti–0.4wt%VGCF as compared to pure Ti, while those values were 30.5% and 2.1% for Ti–0.4wt%Gr. The strengthening mechanism including grain refinement, carbon solid solution strengthening and dispersion hardening of TiC/carbon was discussed in detail.

scholarly journals Nanocrystalline Cr-Ni Alloying Layer Induced by High-Current Pulsed Electron Beam

Nanomaterials ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 74 ◽  
Author(s):  
Lingyan Zhang ◽  
Ching-Tun Peng ◽  
Jintong Guan ◽  
Peng Lv ◽  
Qingfeng Guan ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Electron Beam ◽  
Strengthening Mechanism ◽  
High Current ◽  
Nickel Substrate ◽  
X Ray Diffraction ◽  
Pulsed Electron Beam ◽  
Solid Solution Strengthening ◽  
Transmission Electron ◽  
Solution Strengthening

In this investigation, chromium (Cr) was adopted as an alloying element on a nickel substrate, and the alloying process was materialized via high-current pulsed electron beam (HCPEB) irradiation. X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were also conducted for microstructure characterization. The results showed that after HCPEB irradiation a nanocrystalline Cr-Ni alloying layer was formed and numerous dislocations were generated, resulting in a great deal of diffusion paths for Cr elements. Moreover, properties including hardness, wear and electrochemical performance were significantly improved after HCPEB irradiation, which was mainly due to the formation of the nanocrystalline Cr–Ni alloying layer. In addition, each strengthening mechanism that contributed to the hardness of the HCPEB-irradiated sample was mathematically analyzed, and solid solution strengthening was found to be of great importance.

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