scholarly journals Effect of Nitrogen Content on the Formation of Inclusions in Fe-5Mn-3Al Steels

Crystals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 836 ◽  
Author(s):  
Michelia Alba ◽  
Muhammad Nabeel ◽  
Neslihan Dogan
Keyword(s):  
Nitrogen Content ◽  
Cooling Rate ◽  
Liquid Steel ◽  
Thermodynamic Calculations ◽  
Slow Cooling ◽  
N Content ◽  
Dominant Type ◽  
Gas Purging ◽  
Primary Type ◽  
Pure Al2o3

The effect of N content on the characteristics and formation of inclusions in the Fe-5Mn-3Al steels was investigated in this study. Two synthetic steel melts were produced by two different methods—N2 gas purging and injecting—to introduce nitrogen into the melt. The N content of steel melt varied from 2 to 54 ppm. An increase in the N content to 47 ppm (for 533N-P) and 58 ppm (for 533N-I) increased the total amount of inclusions from 13 to 64 mm−2 and from 21 to 101 mm−2, respectively. The observed inclusions were Al2O3(pure), Al2O3-MnS, AlN(pure), AlN-MnS, AlON, AlON-MnS, and MnS. When the N content was less than 10 ppm, AlN-MnS inclusions were the primary type of inclusions and they formed as solidification products. With an increase in the N content, AlN(pure) inclusions became the dominant type of inclusions as AlN was stable in the liquid steel. These findings were confirmed by thermodynamic calculations. The influence of cooling rate on the types of inclusions was studied and a higher number of AlN-MnS inclusions were observed in samples with slow cooling rate.

scholarly journals Influence of Al and N Content and Cooling Rate on the Characteristics of Complex MnS Inclusions in AHSS

Crystals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1054
Author(s):  
Muhammad Nabeel ◽  
Michelia Alba ◽  
Neslihan Dogan
Keyword(s):  
Cooling Rate ◽  
High Strength Steels ◽  
High Strength ◽  
Slow Cooling ◽  
N Content ◽  
Al Content ◽  
Advanced High Strength Steels ◽  
Cooling Conditions ◽  
Mns Precipitation ◽  
Precipitation Ratio

This study focused on the characteristics of complex MnS inclusions in advanced high strength steels. The effect of metal chemistry (Al and N) and the cooling rate of steel were evaluated by analyzing the inclusions present in five laboratory produced steels. The observed complex MnS inclusions contained Al2O3-MnS, AlN-MnS, and AlON-MnS. An increase in Al content from 0.5% to 6% increased the number of complex MnS inclusions by ~4 times. In comparison, a decrease of ~80% was observed due to the increased N content of steel from <10 ppm to ~50 ppm. MnS precipitation ratio was used to determine the potency of different inclusions forming complex MnS inclusions due to heterogeneous nucleation. It was found that the MnS precipitation ratio of the observed inclusions was related to their misfit with MnS, and it decreased in the order of AlN > AlON > Al2O3. Moreover, it was determined that AlN particles could be easily engulfed at the solidification front relative to Al2O3, which resulted in a higher MnS precipitation ratio for Al2O3 under slow cooling conditions.

scholarly journals Correlation of Processing, Inner Structure, and Part Properties of Injection Moulded Thin-Wall Parts on Example of Polyamide 66

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Dietmar Drummer ◽  
Steve Meister
Keyword(s):  
Cooling Rate ◽  
Injection Moulding ◽  
Degree Of Crystallinity ◽  
Process Conditions ◽  
Thin Wall ◽  
Polyamide 66 ◽  
Slow Cooling ◽  
Cooling Conditions ◽  
Internal Structures ◽  
Wall Injection

In micro- and thin-wall injection moulding the process conditions affect the developed internal structures and thus the resulting part properties. This paper investigates exemplarily on polyamide 66 the interactions of different cooling conditions on the morphological and crystalline structures. The investigations reveal that a slow cooling rate of the melt results in a homogeneous morphology and a higher degree of crystallinity and also a favoured crystalline structure. Consequently, the dielectric behaviour and light transmitting part properties are affected.

Effect of weed management on weeds, and on the nodulation, nitrogenase activity, growth and yield of pea (Pisum sativum)

2006 ◽  
Vol 54 (4) ◽  
pp. 469-485 ◽  
Author(s):  
G. Singh ◽  
D. Wright
Keyword(s):  
Pisum Sativum ◽  
Nitrogen Content ◽  
Weed Management ◽  
Plant Biomass ◽  
Nitrogenase Activity ◽  
Strong Relationship ◽  
Dry Weight ◽  
Growth And Yield ◽  
N Content ◽  
Shoot Dry Weight

Effects of one pre-emergence herbicide (terbutryn/terbuthylazine) and one post-emergence herbicide (bentazone) along with unweeded and hand-weeded controls on weeds and on the nodulation, nitrogenase activity, nitrogen content, growth and yield of pea (Pisum sativum) were studied. Terbutryn/terbuthylazine was applied pre-emergence @ 1.40, 2.80 and 5.60 kg/hawhereas bentazone was sprayed 6 weeks after sowing @ 1.44, 2.88 and 5.76 kg/h. Terbutryn/terbuthylazine controlled all the weeds very effectively, whereas bentazone did not control some weeds such as Polygonum aviculare, Poa annua and Elymus repens. The herbicides decreased the number of nodules, the dry weight of nodules, the nitrogenase activity, the shoot dry weight, the nitrogen content in the straw and seeds, and the seed yield of peas, the effects generally being higher at higher rates of application. The adverse effects of herbicides on these parameters might be due to their effects on plant growth, as both the herbicides are known to adversely affect photosynthesis. Nitrogenase activity did not correlate well with plant-N content or shoot dry weight. However, there was a strong relationship between plant biomass and plant-N content, which suggests that researchers can rely on these parameters for studying the effects of treatments on nitrogen fixation, rather than measuring nitrogenase activity.

Enhancing the electrical conductivity of PP/CNT nanocomposites through crystal-induced volume exclusion effect with a slow cooling rate

2020 ◽  
Vol 183 ◽  
pp. 107663 ◽  
Author(s):  
Jun Wang ◽  
Yasamin Kazemi ◽  
Sai Wang ◽  
Mahdi Hamidinejad ◽  
Mayesha B. Mahmud ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Cooling Rate ◽  
Slow Cooling ◽  
Exclusion Effect

40Ar/39Ar and K–Ar age constraints on shear zone evolution, southern Taltson magmatic zone, northeastern Alberta

1995 ◽  
Vol 32 (3) ◽  
pp. 281-291 ◽  
Author(s):  
H. E. Plint ◽  
M. R. McDonough
Keyword(s):  
Cooling Rate ◽  
Shear Zone ◽  
High Grade ◽  
Slow Cooling ◽  
Rapid Cooling ◽  
Deformational History ◽  
The Mean ◽  
Exhumation Rates ◽  
Northeastern Alberta ◽  
Age Constraints

New 40Ar/39Ar analyses of hornblende, muscovite, biotite, and K-feldspar constrain the timing of deformation and cooling of the southern Taltson magmatic zone, which underwent lower granulite to upper amphibolite grade deformation, in part synchronous with voluminous 1.99–1.92 Ga magmatism. New data are combined with existing K–Ar dates into a regional cooling framework to provide thermotemporal constraints on the deformational history. 40Ar/39Ar hornblende ages of ca. 1900 Ma are interpreted to record relatively rapid cooling following ductile thrusting on the Andrew Lake shear zone, and younger anatectic magmatism. These data, with published K–Ar and U–Pb data, support relatively rapid cooling of the Taltson magmatic zone from monazite closure temperature of 725 °C at ca. 1930 Ma to 525 °C at ca. 1900 Ma. Cooling rate estimates are about 7 °C/Ma, which suggests moderate exhumation rates during the high-grade part of the deformational history. A muscovite 40Ar/39Ar plateau age of 1803 ± 11 Ma is consistent with the mean muscovite K–Ar age of 1792 Ma, indicating regional cooling through about 350 °C at ca. 1800 Ma. 40Ar/39Ar ages from magmatic biotite of 1856 and 1799 Ma also suggest slow cooling during greenschist grade deformation, which can be no older than ca. 1860 Ma. A K-feldspar 40Ar/39Ar age of 1681 Ma provides a lower limit for the time of greenschist grade deformation. Cooling rate estimates during amphibolite to greenschist grade deformation are 1.75–2.25 °C/Ma.

Quench Brittleness of 12%Cr Martensitic Heat-Resistant Steel

2011 ◽  
Vol 479 ◽  
pp. 8-12 ◽  
Author(s):  
Gang Yang ◽  
Zheng Dong Liu ◽  
Shi Chang Cheng ◽  
Mu Xin Yang
Keyword(s):  
Impact Toughness ◽  
Cooling Rate ◽  
Microstructural Characterization ◽  
Temper Brittleness ◽  
Resistant Steel ◽  
Slow Cooling ◽  
Continuous Precipitation ◽  
Heat Resistant Steel ◽  
Heat Resistant ◽  
The Impact

The mechanism of brittleness due to slow cooling during quenching was experimentally investigated in 12% Cr martensitic heat resistant steel. The mechanical property tests and microstructural characterization by SEM、TEM and XRD were conducted. The results showed the impact toughness would decrease with the slowing of cooling rate during quenching, and the low cooling rate within the temperature range from 820 to 660 °C played a significant effect on the impact toughness . Different from the mechanism of temper brittleness, the main causes of embrittlement due to the slow cooling upon quenching were both the continuous precipitation of M23C6 along prior austenite grain boundaries during the process of slow cooling and that of M2C along prior residual austenite film during tempering, and this kind of quench brittleness was nonreversal.

Nitrogen Porosity in Nitrogen Bearing Austenitic Stainless Steel

2005 ◽  
Vol 475-479 ◽  
pp. 2679-2682 ◽  
Author(s):  
Seong Ho Yang ◽  
Zin Hyoung Lee
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Nitrogen Content ◽  
Cooling Rate ◽  
Nitrogen Gas ◽  
Solidification Sequence

The formation of nitrogen gas pores is affected by various factors such as solidification sequence, solubility of nitrogen, cooling rate, melt pressure, nitrogen content etc. Nitrogen porosity in Fe-16Cr-3Ni-9Mn austenitic stainless steel solidifying to primary d-ferrite that can cause nitrogen gas pores was examined. And also the effect of nitrogen content, cooling rate and melt pressure on nitrogen porosity was investigated.

scholarly journals Plant DNA methylation is sensitive to parent seed N content and influences the growth of rice

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Xiaoru Fan ◽  
Laihua Liu ◽  
Kaiyun Qian ◽  
Jingguang Chen ◽  
Yuyue Zhang ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Plant Growth ◽  
Nitrogen Content ◽  
Nitrogen Stress ◽  
Wild Type ◽  
High Nitrogen ◽  
N Content ◽  
Plant Nitrogen ◽  
Overexpression Line ◽  
N Deficiency

Abstract Background Nitrogen (N) is an important nutrient for plant growth, development, and agricultural production. Nitrogen stress could induce epigenetic changes in plants. In our research, overexpression of the OsNAR2.1 line was used as a testing target in rice plants with high nitrogen-use efficiency to study the changes of rice methylation and growth in respond of the endogenous and external nitrogen stress. Results Our results showed that external N deficiency could decrease seed N content and plant growth of the overexpression line. During the filial growth, we found that the low parent seed nitrogen (LPSN) in the overexpression line could lead to a decrease in the filial seed nitrogen content, total plant nitrogen content, yield, and OsNAR2.1 expression (28, 35, 23, and 55%, respectively) compared with high parent seed nitrogen (HPSN) in high nitrogen external supply. However, such decreases were not observed in wild type. Furthermore, methylation sequencing results showed that LPSN caused massive gene methylation changes, which enriched in over 20 GO pathways in the filial overexpression line, and the expression of OsNAR2.1 in LPSN filial overexpression plants was significantly reduced compared to HPSN filial plants in high external N, which was not shown in wild type. Conclusions We suggest that the parent seed nitrogen content decreased induced DNA methylation changes at the epigenetic level and significantly decreased the expression of OsNAR2.1, resulting in a heritable phenotype of N deficiency over two generations of the overexpression line.

Connectivity and flux pinning improvements in Ag-clad BSCCO-2223 tapes produced by changes in the cooling rate

1997 ◽  
Vol 12 (11) ◽  
pp. 2997-3008 ◽  
Author(s):  
J. A. Parrell ◽  
D. C. Larbalestier ◽  
G. N. Riley ◽  
Q. Li ◽  
W. L. Carter ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Critical Temperature ◽  
Cooling Rate ◽  
Flux Pinning ◽  
Irreversibility Field ◽  
Superconducting Properties ◽  
Temperature Transition ◽  
Slow Cooling ◽  
Reaction Heat ◽  
Final Reaction

The rate at which Ag-clad (Bi, Pb)2Sr2Ca2Cu3Ox tapes are cooled from their final reaction heat treatment influences both the intergranular connectivity and intragranular flux pinning strength of the polycrystalline filaments. As the cooling rate from 825 °C to 730 °C in 7.5% O2 was decreased over a range of 5 °C/min to 0.005 °C/min, Jc (77 K, 0 T) increased from ∼8 to ∼24 kA/cm2, and the irreversibility field increased from, ∼120 to, ∼200 mT. The Jc (4.2 K, 0 T) increased in a similar fashion. Cooling slowly also sharpened the critical temperature transition and increased the critical onset temperature from 107 K to 109 K. These improvements in the superconducting properties occurred despite partial decomposition of the (Bi, Pb)2Sr2Ca2Cu3Ox phase into non-superconducting impurity phases during the slow cooling. A microstructural basis for these multiple effects is described.

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