scholarly journals Scale resistance increase in hot rolling rollers by powder wire welding deposition

2020 ◽  
Vol 2020 (10) ◽  
pp. 34-39
Author(s):  
Evgenyi Yeryomin ◽  
Aleksandr Losev ◽  
Ivan Ponomaryov ◽  
Sergey Borodikhin
Keyword(s):  
Hot Rolling ◽  
Chemical Compounds ◽  
Scale Formation ◽  
Powder Wire ◽  
High Scale ◽  
Resistance Increase ◽  
Scale Resistance ◽  
Better Than

The application of PP30N8H6M3STYu powder wire is considered which ensures high scale-resistance of welded metal. It is defined that the scale formation indices of 30N8H6M3STYu metal are much better than those in 30H2V8F steel at the temperature of 900ºC. It is shown that the scale base of 30N8H6M3STYu metal is chemical compounds of Fe2O3, Fe3O4, Cr2FeO4, Fe2NiO4 and Fe3N.

Investigation of different inorganic chemical compounds as hot metal forming lubricant by pin-on-disc and hot rolling

2018 ◽  
Vol 125 ◽  
pp. 110-120 ◽  
Author(s):  
Shaogang Cui ◽  
Hongtao Zhu ◽  
Shanhong Wan ◽  
Bach Tran ◽  
Long Wang ◽  
...  
Keyword(s):  
Hot Rolling ◽  
Metal Forming ◽  
Chemical Compounds ◽  
Hot Metal ◽  
Pin On Disc ◽  
Inorganic Chemical

Effect of the Temperature–Speed Hot-Rolling Conditions on Scale Formation

2021 ◽  
Vol 2021 (13) ◽  
pp. 1766-1770
Author(s):  
S. I. Platov ◽  
R. R. Dema ◽  
O. R. Latypov ◽  
V. S. Banshchikov ◽  
V. A. Mustafin ◽  
...  
Keyword(s):  
Hot Rolling ◽  
Scale Formation ◽  
Hot Rolling Conditions

scholarly journals On the Culture of the Plankton Diatom Thalassiosira grauida Cleve, in Artificial Sea-water

1914 ◽  
Vol 10 (3) ◽  
pp. 417-439 ◽  
Author(s):  
E. J. Allen
Keyword(s):  
Organic Compound ◽  
Culture Medium ◽  
Sea Water ◽  
Chemical Compounds ◽  
Distilled Water ◽  
Artificial Medium ◽  
Plant Life ◽  
Specific Substance ◽  
Vigorous Growth ◽  
Better Than

1. Attempts to obtain good cultures of Thalassiosira gravida in a purely artificial medium, made by dissolving in doubly distilled water Kahlbaum's pure chemicals in the proportions in which the salts occur in sea-water, adding nitrates, phosphates and iron according to Miquel's method and sterilizing the medium, have not succeeded.If, however, a small percentage of natural sea-water (less than 1 per cent will produce a result) be added to the artificial medium and the whole sterilized excellent cultures are obtained, which are often better than any which have been got when natural sea-water forms the foundation of the culture medium.The result appears to be due to some specific substance present in minute quantity in the natural sea-water which is essential to the vigorous growth of the diatoms. The nature of this substance it has not been possible to determine, but some evidence seems to suggest that it is a somewhat stable organic compound.Provided the 1 per cent of natural sea-water is added, the various constituents of the artificial sea-water forming the basis of the culture medium can be varied in amount within wide limits. The salinity of the medium can also be considerably altered without serious detriment to the cultures.The experiments recorded are of interest as furnishing another instance of the importance in food substances of minute traces of particular chemical compounds. They may also eventually throw light upon the nature of the conditions in the sea which are specially favourable to the production of plant life and therefore also of the animal life which that plant life sustains.

scholarly journals Prevention of Red Scale Formation during Hot Rolling of Steels.

1995 ◽  
Vol 35 (7) ◽  
pp. 886-891 ◽  
Author(s):  
Hikaru Okada ◽  
Tomoki Fukagawa ◽  
Haruhiko Ishihara ◽  
Atsuki Okamoto ◽  
Masatoshi Azuma ◽  
...  
Keyword(s):  
Hot Rolling ◽  
Scale Formation

scholarly journals Comparison of Chemical Compounds and Their Influence on The Taste of Coffee Depending on Green Beans Storage Conditions

2021 ◽  
Author(s):  
Magdalena Zarebska ◽  
Natalia Stanek ◽  
Krzysztof Barabosz ◽  
Anna Jaszkiewicz ◽  
Renata Kulesza ◽  
...  
Keyword(s):  
Storage Temperature ◽  
Chemical Compounds ◽  
Treatment Method ◽  
Storage Conditions ◽  
Sensory Profile ◽  
Roasted Coffee ◽  
Green Beans ◽  
Grain Processing ◽  
Better Than ◽  
Natural Way

Abstract Currently, there is no technology for storing green coffee (GC), which results in obtaining high-quality roasted coffee (RC). The aim of this study was evaluating the effects of storage temperature (-10, 5, 10, 18, 20ºC, uncontrolled), post-harvest treatment method (natural (N), washed (W)) and type of packaging material (GrainPro (G), jute (J) bags) on content of chlorogenic acids, caffeine and trigonelline as also on sensory profile of GC from “specialty’ sector after 12 months of measured storage. HPLC results showed that GrainPro bags preserve considered compounds better than jute. Exception was 10oC chamber, where in the samples from jute have been reported higher contents of all analyzed compounds. Also natural way of grain processing retains more assayed compounds. The best results were obtained in 10oC for jute both, natural and washed, where the highest level of all considered compounds were noted. The tendency was supported by the sensory analysis.

Radiocarbon dating by accelerator mass spectrometry: some recent results and applications

1987 ◽  
Vol 323 (1569) ◽  
pp. 57-73 ◽  
Keyword(s):  
Mass Spectrometry ◽  
Accelerator Mass Spectrometry ◽  
Radiocarbon Dating ◽  
Chemical Compounds ◽  
Environmental Research ◽  
Specific Chemical ◽  
Archaeological Material ◽  
Comparable Accuracy ◽  
Different Sources ◽  
Better Than

14 C differs from other nuclides measured by accelerator mass spectrometry (AMS) in that an extensive database of dates already exists, AMS dates should therefore have comparable accuracy, and the measurement of isotopic ratios to better than 1 % , which was an important technical goal, has been reached. The main advantage of being able to date samples 1000 times smaller than previously lies in the extra selectivity that can be employed. This is reflected in the results and applications. Selection can apply at several levels; from objects th at formerly contained too little carbon, to the choice of archaeological material, to the extraction of specific chemical compounds from a complex environmental sample. This is particularly useful in removing uncertainty regarding the validity of a date, since a given sample may comprise carbon atoms from different sources each with their own 14 C ‘age’. Examples from archaeological and environmental research illustrating these points are given. 14 C dating by AMS differs from conventional radiocarbon dating by having the potential to measure much lower levels of 14 C, and therefore should double the time span of the method. This potential has not yet been realized because of sample contamination effects, and work in progress to reduce these is described.

THE TEST OF ANTIOXIDANT ACTIVITIES WITH COMPARISON OF EXTRACTION METHODS FROM ROBUSTA COFFEE SEEDS (Coffea canephora)

2019 ◽  
Vol 1 (02) ◽  
pp. 60-63
Author(s):  
Novi Fajar Utami ◽  
Nhadira Nhestricia
Keyword(s):  
Antioxidant Activity ◽  
Antioxidant Activities ◽  
Chemical Compounds ◽  
Extraction Methods ◽  
Coffea Canephora ◽  
Robusta Coffee ◽  
Coffee Beans ◽  
Method Of Extraction ◽  
Coffee Seed ◽  
Better Than

The content of robusta coffee include alkaloids, flavonoids, saponin, tannins, caffeine, and phenol. Differences in the method of extraction of a plant can cause differences in the number of chemical compounds. The purpose of this study was to determine the phytochemical characteristics and antioxidant activity in robusta coffee beans extracted by maceration and sonication method. Antioxidant activity was performed by the method of DPPH (2,2-diphenyl-1-picrylhydrazyl) by spectrophotometry. The results showed that phytochemical characteristics of robusta coffee extract of maceration and sonication contain the same chemical compounds, namely alkaloids, flavonoids, tannins, and saponins. The antioxidant activity of robusta coffee seed extract of sonication result has IC50 of 54,14 ppm which is better than the extract of robusta coffee beans from maceration.

Turn-Up and Turn-Down in Hot Rolling: A Study on a Model Mill Using Plasticine

1972 ◽  
Vol 14 (4) ◽  
pp. 245-254 ◽  
Author(s):  
S. A. E. Buxton ◽  
S. C. Browning
Keyword(s):  
Hot Rolling ◽  
Surface Friction ◽  
Scale Model ◽  
Speed Ratio ◽  
Strain Component ◽  
Full Size ◽  
Plastic Yield ◽  
Steel Slabs ◽  
Work Rolls ◽  
Better Than

Turn-up and turn-down is a phenomenon which occurs in the hot rolling of flat products when the nose of a slab, or the whole slab, curls up or down upon emerging from the rolls and remains deformed unless subsequently straightened. Turn-up and turn-down can be troublesome to production, since it can cause damage to the mill rolls, housing, and run-out tables and can also cause production delays due to the difficulty of re-rolling a deformed slab. The object of this paper is to determine the main factors governing the phenomenon, to obtain quantitative relationships between causes and effects, and to suggest means of preventing curvature occurring. The best approach was considered to be a scale model using plasticine to simulate the hot metal. As a basis for the work, several dimensionless ratios are formed which have to be the same in both model and full size mill, if the model is to be both dynamically and geometrically similar. In the more important dimensionless ratios, account is taken of the plastic yield characteristics of the material, including the rate-of-strain component, of the stresses due to surface friction and gravity, and finally of the ratio of roll speeds. The results are compared with some previous work by others on steel slabs using a full size mill. In all respects, the results agree closely. The most significant factor affecting turn-up and turn-down is the ratio of surface speeds of the two work-rolls. Curvature is proportional to this speed ratio, but slipping at the rolls may modify this relationship. For a given angle of entry, the ratio of torque upon each roll is a function of the speed ratio. Angle of entry has negligible effect on turn-up and turn-down, but has a powerful effect upon the torque ratio. Slip is very undesirable and it appears that the roll surface finish should not be better than necessary if slip is to be avoided. To produce a flat slab, a speed ratio of about 0·97 is required in the model. In practice, this may be achieved either directly by controlling the speed ratio, or indirectly by controlling the torque ratio, provided the angle of entry is constant.

Comparative Study on Microstructure and Texture of Ti-IF Steel Sheets Produced by Different Hot Rolling Processing

2011 ◽  
Vol 418-420 ◽  
pp. 726-730
Author(s):  
Yun Li Feng ◽  
Ming Cai ◽  
Li Bin Chen
Keyword(s):  
Grain Size ◽  
Hot Rolling ◽  
Diffraction Method ◽  
Rolling Process ◽  
X Ray Diffraction ◽  
Steel Sheets ◽  
Size Number ◽  
Average Grain Size ◽  
Metallographic Observation ◽  
Better Than

It was analyzed by metallographic observation and X-ray diffraction method that the microstructure and texture in two kinds of Ti-IF steels, which produced by different hot rolling process,and it also was discussed that the formability and the texture in Ti-IF steels. The results showed that the microstructures of these two kinds of steels are Equiaxed ferrite grains, but the grain sizes are greatly different. Respectively the average grain size of steel A and B are 24.85μm and 11.85μm, and the average grain size number are 7.4 and 9.5. The {111} texture of steel B is stronger than A, besides, the deep drawing properties of steel B is better than A in the reason that disadvantaged texture{001} and {112} are not founded in steel B.

Alloy Design and Application for Avoiding Carbide Network of CrWMn Steel by Phase Equilibrium Thermodynamic Method

2013 ◽  
Vol 690-693 ◽  
pp. 91-96
Author(s):  
Yong Qing Ma ◽  
Xiao Jing Zhang ◽  
Yu Fen Liang
Keyword(s):  
Hot Rolling ◽  
Alloy Design ◽  
Equilibrium Thermodynamic ◽  
Cooling Process ◽  
Carbide Network ◽  
Boundary Precipitation ◽  
Equilibrium Phases ◽  
Hot Rolling Conditions ◽  
Research Show ◽  
Better Than

By the equilibrium phases of the steels with temperature, the causation of being carbide network of CrWMn steel frequently in the manufacture was analyzed, and an alloy design for avoiding carbide network of CrWMn steel was researched. The analyse and research show that in austenite area the boundary precipitation of M3C and M6C carbides during cooling process after forging or hot rolling is preferential origin of carbide network, and in later ferrite area the precipitation and congregation of the carbides should lead on network aggravation. When CrWMn steel adding 0.3~0.4Mo as supplement, in austenite area M3C carbide disappears and M23C6 carbide increases, and it is conceivable of lightenning congregation to austenite boundary as the transformation of M23C6 and M6C reciprocally, and the distribution of diversified carbides should become fine too. The practice results show that the carbide network of CrWMnMo0.35 steel is avoided under normal forging or hot rolling conditions, and the hardness after quenching at 850°C and tempering at 200°C is HRC62~63, which is agreement with alloy design forecast. The experiment and application show that the performance of CrWMnMo0.35 steel is better than that of customary CrWMn steel for machinery knives.

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