An integrated approach for production of stainless steel master alloy from a low grade chromite concentrate

2018 ◽  
Vol 335 ◽  
pp. 103-113 ◽  
Author(s):  
Deqing Zhu ◽  
Congcong Yang ◽  
Jian Pan ◽  
Liming Lu ◽  
Zhengqi Guo ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Master Alloy ◽  
Integrated Approach ◽  
Low Grade ◽  
Chromite Concentrate

scholarly journals Corrosion Behaviour Of Sintered AISI 316L Stainless Steel Modified With Boron-Rich Master Alloy In 0.5M NaCl Water Solution

2015 ◽  
Vol 60 (3) ◽  
pp. 1795-1800 ◽  
Author(s):  
A. Szewczyk-Nykiel ◽  
M. Skałoń ◽  
J. Kazior
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Master Alloy ◽  
Corrosion Behaviour ◽  
Water Solution ◽  
Superficial Layer ◽  
Aisi 316L ◽  
Near Surface ◽  
Surface Areas ◽  
316L Austenitic Stainless Steel

Abstract Present study describes results of research conducted on sinters manufactured from a powdered AISI 316L austenitic stainless steel modified with an addition of boron-rich master alloy. The main aim was to study impact of the master alloy addition on a corrosion resistance of sinters in 0.5M water solution of NaCl. In order to achieve it, a potentiodynamic method was used. Corrosion tests results were also supplemented with a microstructures of near-surface areas. Scanning electron microscope pictures of a corroded surfaces previously exposed to the corrosive environment were taken and compared. It was successful to increase the corrosion resistance of AISI 316L sinters modified with master alloy. It was also successful in particular samples to obtain a densified superficial layer not only on the sinters sintered in the hydrogen but also on sinters sintered in the vacuum. No linear correlation between presence of the densified superficial layer and the enhanced corrosion resistance was noticed.

scholarly journals Reactivity of Low-Grade Chromite Concentrates towards Chlorinating Atmospheres

Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4470
Author(s):  
Ndue Kanari ◽  
Eric Allain ◽  
Lev Filippov ◽  
Seit Shallari ◽  
Frédéric Diot ◽  
...  
Keyword(s):  
Activation Energy ◽  
Thermogravimetric Analysis ◽  
Thermal Behavior ◽  
Gas Phase ◽  
Low Grade ◽  
Bearing Material ◽  
High Chromium ◽  
Chromyl Chloride ◽  
Chromite Concentrate ◽  
Iron Chromium

The most economically important iron-chromium bearing minerals is chromite. In natural deposits, iron(II) is frequently substituted by magnesium(II) while chromium(III) is replaced by aluminum(III) and/or iron(III) forming a complex chromium bearing material. The majority of mined chromite is intended for the production of ferrochrome which requires a chromite concentrate with high chromium-to-iron ratio. Found mostly in the spinel chromite structure, iron cannot be removed by physical mineral processing methods. In this frame, the present work deals with the reaction of chlorine and chlorine+oxygen with selected samples of chromite concentrates for assessing the reactivity of their components towards chlorinating atmosphere, allowing the preferential removal of iron, hence meeting the chromite metallurgical grade requirements. Isothermal thermogravimetric analysis was used as a reliable approach for the kinetic reactivity investigation. Results indicated a wide difference in the thermal behavior of chromite constituents in a chlorinating atmosphere when considering their respective values of apparent activation energy oscillating from about 60 to 300 kJ/mol as a function of the sample reacted fraction. During the chromite treatment by chlorine in presence of oxygen, chromium was recovered as liquid chromyl chloride by condensation of the reaction gas phase.

scholarly journals Effect of Carbon Content and Elements Mo and V on the Microstructure and Properties of Stainless Steel Powder Surfacing Layer

Coatings ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 371
Author(s):  
Taixu Xu ◽  
Chongyi Wei ◽  
Xiao Han ◽  
Jihui Liu ◽  
Zhijun He ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Wear Resistance ◽  
Corrosion Resistance ◽  
Impact Toughness ◽  
Carbon Content ◽  
Steel Powder ◽  
Stainless Steel Powder ◽  
Low Grade ◽  
Microstructure And Properties ◽  
The Impact

This study evaluated the effect of an increase in carbon content and the presence of the elements Mo and V on the microstructure and properties of the surfacing layer of stainless steel powder for knives and scissors production. Various types of high-quality stainless steel powder (5Cr13, 8Cr13, and 8Cr13MoV) were deposited on the surface of low-grade stainless steel used to produce knives and scissors (2Cr13). The microstructure, comprehensive hardness, wear resistance, impact toughness, and corrosion resistance of the stainless steel powder surfacing layers were tested and analyzed. Results indicate that the increase in carbon content and the presence of Mo and V improve the comprehensive hardness and wear resistance of the stainless steel powder surfacing layer, and both exert the superposition effect. However, the increase in carbon content and the presence of Mo and V slightly influence the impact toughness of the surfacing layer. In addition, the increase in carbon content significantly reduces the corrosion resistance of the surfacing layer. This adverse effect is reduced when Mo and V exist. Other advantages of the presence of Mo and V in the stainless steel powder surfacing layer include the refinement of grain size, reduction of carbide particle size, and improvement of the metallurgical bonding of the surfacing layer and the matrix.

Solidification structure refining of 409L ferritic stainless steel using Fe-Ti-N master alloy

2012 ◽  
Vol 18 (1) ◽  
pp. 47-53 ◽  
Author(s):  
Chao Wang ◽  
Haiyan Gao ◽  
Yongbing Dai ◽  
Jun Wang ◽  
Baode Sun
Keyword(s):  
Stainless Steel ◽  
Ferritic Stainless Steel ◽  
Master Alloy ◽  
Solidification Structure

Effect of Adding a Type of Binder Phase on The Microstructure, Properties and Heat Treatment of Steel Bonded TiC Cermets

2007 ◽  
Vol 534-536 ◽  
pp. 1161-1164 ◽  
Author(s):  
Akthar Farid ◽  
Shi Ju Guo ◽  
Jawad Ali Shah ◽  
Pei Zhong Feng
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Stainless Steel ◽  
Master Alloy ◽  
Phase Variation ◽  
Binder Phase ◽  
Steel Matrix ◽  
Microstructure And Mechanical Properties ◽  
Maraging Stainless Steel

Particulate TiC reinforced 465 maraging stainless steel matrix Cermets were processed by conventional P/M. The binder phase was added in the form of elemental powders and master alloy powders. The microstructures, binder phase variation with TiC content and mechanical properties were evaluated. The addition of a type of binder phase largely effects the microstructure and mechanical properties. When a master alloy binder phase was used the microstructure showed interphase debondings, microcracks and large growths of TiC particles. Where as, elemental powders in the composition of binder phases showed defect free microstructure of steel bonded cermets. The binder phase variation from starting composition was observed with increase in wt% TiC content and this variation was higher when the master alloy powders were used as a binder. After heat treatment and aging, an increase in hardness was observed. The increase in hardness was attributed to the aging reaction in maraging stainless steel. The response to heat treatment was decreased with an increase in TiC content due to the shift of binder phase from the starting composition.

scholarly journals On the Flotation of a Low Grade Chromite Ore

2012 ◽  
Vol 6 (1) ◽  
pp. 19
Author(s):  
Tamam T. A. K ◽  
Ahmed A.S.Seifelnasr
Keyword(s):  
Oleic Acid ◽  
Iron Oxides ◽  
Froth Flotation ◽  
Pulp Density ◽  
Operating Parameters ◽  
Low Grade ◽  
High Grade ◽  
Chromite Ore ◽  
Chromite Concentrate ◽  
Representative Samples

This study is concerned with the processing of low grade chromite ores, Ingassena Hills by froth flotation techniques. For this purpose, representative samples were taken from four different mines. Mineralogical examinations indicated that, the major minerals are chromite and serpentine .Olivine, iron oxides and talc have been identified as minor minerals. Adequate degree of liberation of chromite was obtained by grinding the ore to minus 177µm. Froth flotation was used to upgrade that particular chromite ore. Oleic acid was used as collector. Several operating parameters influencing the floatability of both high grade chromite and serpentine were investigated. These include the concentrations of the collector and depressant, pulp pH and conditioning time. From an ore feed grading 20.27% Cr2O3, a chromite concentrate of 28.71% Cr2O3 with recovery of 94.54 % could be obtained by flotation at collector dosage of 0.300 kg /t , neutral pulp (pH 9) ,conditioning time ,2min ,and pulp density, 20%.

Enhanced sintering of austenitic stainless steel powder AISI 316L through boron containig master alloy addition

2012 ◽  
Vol 57 (3) ◽  
pp. 789-797 ◽  
Author(s):  
M. Skałon ◽  
J. Kazior
Keyword(s):  
Stainless Steel ◽  
Liquid Phase ◽  
Master Alloy ◽  
Stainless Steels ◽  
Austenitic Stainless Steels ◽  
Hydrogen Atmosphere ◽  
Aisi 316L ◽  
Sintering Process ◽  
Sintered Iron ◽  
Sintering Atmosphere

It is well known that boron is widely used in order to enhance sintering process for obtaining high density of sintered iron alloys. It was found that even a small amount of elemental boron added to iron based powder compacts, produces significant increase in densification rate upon formation of a liquid phase. Due to the attractive characteristic the use of boron has also been actively investigated for enhancing sintering stainless steels powders. In present research boron was added as a part of master alloy, which has been designed to provide the formation of wetting liquid phase, with accomplished characteristics for manufacturing controlled densification of sintered austenitic stainless steels powders AISI 316L. In this paper the influence of sintering atmosphere and the boron in 0,1; 0,2; 0,3 and 0,4 wt. % amount on the density, microstructure and selected properties of sintered austenitic stainless steels were reported. Green compacts obtained by cold compaction at 600 MPa reached densities around 6,2 g/cm3. The sintering process was carried out both in pure dry hydrogen atmosphere and in vacuum at temperature 1240°C using dilatometer Netzsch DIL 402C. In order to interpret the influence of sintering atmosphere and boron content on the sintering behaviour of boron alloyed austenitic stainless steels powders during heating and isothermal holding, the evolution of the dilatometric curves have been discussed. The as-sintered microstructures were characterized under the SEM (EDS), while the pore morphology by the image analysis. In conclusion it could be affirmed that the addition of the master alloy containing boron to austenitic stainless steels powders, produces a permanent liquid phase that enhances densification compacts during sintering, in particular in hydrogen atmosphere. For this reason the results are promising from a technological point of view, because boron addition could extend applications of sintered stainless steel both with respect to lower sintering temperature and shorter time necessary to obtain well rounded pores which are desirable with respect to mechanical properties and corrosion resistance.

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