Surface Decarburization Behavior of Spring Steel 60Si2MnA under AC1 Temperature and in Temperature Range AC3-G

2015 ◽  
Vol 817 ◽  
pp. 132-136 ◽  
Author(s):  
Fan Zhao ◽  
Chao Lei Zhang ◽  
Qi Xiu ◽  
Yao Tan ◽  
Shang Ye Zhang ◽  
...  
Keyword(s):  
Heating Temperature ◽  
Functional Relation ◽  
Heating Time ◽  
Spring Steel ◽  
Temperature Range ◽  
Small Change ◽  
Decarburized Layer ◽  
Surface Decarburization

Surface decarburization of spring steel 60Si2MnA heated under AC1 temperature and in temperature range of AC3-G was investigated. The results show that under the AC1 temperature, pearlite spheroidization and surface decarburization were carried out simultaneously and had a mutual promotion relationship. In the temperature range of AC3-G, decarburized layer consisted of complete and partial decarburization, and the complete decarburized depth increased but the partial decarburized depth just a small change with the increase of heating time. Besides, when heating temperature was 790 °C, functional relation between the total decarburized depth, the complete decarburized depth and the heating time follows the formula of and , respectively.

scholarly journals Ferrite Decarburization of High Silicon Spring Steel in Three Temperature Ranges

2016 ◽  
Vol 61 (3) ◽  
pp. 1715-1722 ◽  
Author(s):  
F. Zhao ◽  
C.L. Zhang ◽  
Y.Z. Liu
Keyword(s):  
Incubation Period ◽  
Ambient Air ◽  
Spring Steel ◽  
Experimental Results ◽  
Temperature Range ◽  
Temperature Ranges ◽  
High Silicon ◽  
Silicon Spring ◽  
Oxidation Loss ◽  
Surface Decarburization

Abstract Surface decarburization of high silicon spring steel in ambient air was studied. The experimental results confirmed the decarburized mechanism under AC1 temperature, in the temperature range of AC1-AC3 and AC3-G. Under AC1 temperature, pearlite spheroidization and surface decarburization are carried out simultaneously and pearlite spheroidization is reinforced. Considering the oxidation loss depth, the “true ferrite decarburized depth” at 850 °C (AC3-G) is still smaller than that at 760°C (AC1-AC3). That is because an “incubation period” must pass away before ferrite decarburization occurs in the temperature range of AC3-G, and the ferrite decarburized rate is limited to being equal to the partial decarburized rate.

scholarly journals NAFTOS PRODUKTŲ GARAVIMO EKSPERIMENTINIAI TYRIMAI / EXPERIMENTAL RESEARCH OF PETROLEUM PRODUCTS EVAPORATION

2019 ◽  
Vol 11 (0) ◽  
pp. 1-5
Author(s):  
Jurgita Aleknaitė ◽  
Dainius Paliulis ◽  
Rasa Vaiškūnaitė
Keyword(s):  
Heavy Metals ◽  
Heating Temperature ◽  
Petroleum Products ◽  
Heating Time ◽  
Oil Products ◽  
Toxic Substances ◽  
Temperature Range ◽  
Used Oil ◽  
Heavy Soil ◽  
The Cost

Oil products are usually released into the environment during transportation of oil, from storage, oil bases or accidents, accounting for about 60% of total soil pollution. Heavy metals, phenols, cyanides, aromatic hydrocarbons (benzene, toluene, ethylbenzene, xylene) also enter the soil together with oil products. After the contamination enters the soil, it affects the pH of the soil, the activity of the biota weakens due to the toxic elements that react with oxygen, the soil degradation increases. In the course of the dissemination of these pollutants, not only the soil, but also groundwater is contaminated – pollution by oil products and heavy metals creates 53% of all groundwater pollution. The aim of the research is to determine the lowest possible optimal temperature by choosing the temperature range of the heating temperature (100−300 °C) and to investigate the dependence of evaporation of oil products on the heating time. The minimum temperature is required to preserve the soil’s properties, reduce the amount of energy used and the cost of the method. During the heat treatment of the selected oil products, the vapor passes through the condenser and is collected in the form of a liquid, avoiding leaks, which is a safe way if toxic substances are potentially exposed at the site of heating (the method safely removes pollutants from mixtures). It has been established that in the temperature range 250−300 °C, clean oil evaporates intensively and achieve 90.1−97.1% efficiency over 2 hours and the maximum evaporation rate is at the first hour, in the case of used oil, an efficiency of 38.6−60.6% is achieved and vapor intensity at maximum after 2 hours of evaporation. This heating technology can be used to clean heavy soil fractions from contaminated oil products, and comparatively low temperatures (250−300 °C) will have less harm to soil properties than high-temperature methods (burning, glazing, pyrolysis).

scholarly journals Study on Ultra-High Temperature Contact Solution Treatment of Al–Zn–Mg–Cu Alloys

Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 842
Author(s):  
Wenming Jin ◽  
Jianhao Yu ◽  
Zhiqiang Zhang ◽  
Hongjie Jia ◽  
Mingwen Ren
Keyword(s):  
Heating Temperature ◽  
Solution Treatment ◽  
Strengthening Mechanism ◽  
Heating Time ◽  
Solution Time ◽  
Solution Temperature ◽  
Second Phase ◽  
Total Strength ◽  
Cu Alloys ◽  
Short Heating Time

Contact solution treatment (CST) of Al–Zn–Mg–Cu alloys can shorten solution time to within 40 s in comparison with 1800 s with traditional solution treatment using a heating furnace. Heating temperature is the key factor in solution treatment. Considering the short heating time of CST, the ultra-high solution temperature over 500 °C of Al–Zn–Mg–Cu alloys was studied in this work. The effects of solution temperatures on the microstructures and the mechanical properties were investigated. The evolution of the second phases was explored and the strengthening mechanisms were also quantitatively evaluated. The results showed that solution time could be reduced to 10 s with the solution temperature of 535 °C due to the increasing dissolution rate of the second phase and the tensile strength of the aged specimen could reach 545 MPa. Precipitation strengthening was the main strengthening mechanism, accounting for 75.4% of the total strength. Over-burning of grain boundaries occurred when the solution temperature increased to 555 °C, leading to the deterioration of the strength.

Numerical Simulation and Process Optimization of Automotive Friction Materials in Warm Pressing Forming

2013 ◽  
Vol 788 ◽  
pp. 57-60
Author(s):  
Chun Cao ◽  
Chun Dong Zhu ◽  
Chen Fu
Keyword(s):  
Process Optimization ◽  
Heating Temperature ◽  
Maximum Energy ◽  
Heating Time ◽  
Product Performance ◽  
Forming Process ◽  
Friction Materials ◽  
Forming Technology ◽  
The Relationship ◽  
Temperature Heating

Warm pressing forming technology has been gradually applied to the forming of automotive friction materials. How to ensure product performance to achieve the target at the same time achieve the maximum energy saving is the research focus of this study. In this paper, by using finite element method, the field of automotive friction materials in warm pressing forming was analyzed, reveals the relationship between the temperature field and the heating temperature/heating time. Furthermore, the energy consumption was analyzed and compared it with hot pressing forming process. The results will have significant guiding to the process optimization in warm pressing forming.

Application Self-Regulating Heating Cable Curing of Concrete in Winter

2014 ◽  
Vol 638-640 ◽  
pp. 1531-1535 ◽  
Author(s):  
Jin Bao Guo ◽  
Lin Liu ◽  
Qiang Wang
Keyword(s):  
Heat Dissipation ◽  
Heating Temperature ◽  
Heating Time ◽  
Minimum Length ◽  
It Use ◽  
Heating Efficiency ◽  
Cable Length ◽  
Heating Cable ◽  
Curing Methods ◽  
Two Parameters

In order to solve the shortcomings of traditional methods of concrete curing in winter, proposed self-regulating heating cable new concrete curing methods. Several aspects were considered, about the heating cable length and heating time, heating temperature. According to energy conservation, heating and heat dissipation balance, derived formulas of heating cable normal use length and minimum. As conclusions is shown, first, the normal length design can controlled better heating temperature, it use the cable length and heating time, heating temperature two parameters to control the other parameters. Second, it is better heating efficiency, can be the overall warming state quickly. In addition, when the concrete pouring temperature is above 10 °C, it is not need additional heating, and it can choose minimum length design formula.

Resistance Welding Process Development and Optimization for Recycled High-Density Polyethylene (HDPE)

2015 ◽  
Author(s):  
Peter F. Baumann ◽  
Lucas Sendrowski
Keyword(s):  
Tensile Strength ◽  
Response Surface ◽  
High Density Polyethylene ◽  
Heating Temperature ◽  
Base Material ◽  
Heating Time ◽  
High Density ◽  
Hot Plate ◽  
Initial Testing ◽  
Hot Plate Welding

Large recycled high-density polyethylene (HDPE) structural members, difficult to manufacture by extrusion processes, have been created by the hot plate welding of simple plastic lumber sections. Hot plate welding generates better joint strength than any other welding method currently employed in plastic manufacturing. However, to achieve the desired temperature of the thick plate to melt the polymer uniformly, the process needs a high amount of heat energy requiring furnace (or resistance) heating of a considerable mass. A new method which could combine the heating element and a thin plate into one source could be more efficient in terms of heat loss and thus energy used. The premise of this investigation is to replace the hot plate with a very thin piece of high resistance nickel-chromium alloy ribbon to localize the application of heat within a plastic weld joint in order to reduce energy loss and its associated costs. This resistance ribbon method uses electrical current to reach an adequate temperature to allow for the welding of the HDPE plastic. The ribbon is only slightly larger than the welding surface and very thin to reduce the loss of excess heat through unused surface area and thick sides. The purpose of this project was to weld recycled high-density polyethylene (HDPE) using resistance welding and to match the tensile strength results considered acceptable in industry for hot plate welding, that is, equal to or greater than 80% of the base material strength. Information obtained through literature review and previous investigations in our laboratories established welding (heating) temperature and time as testing factors. Designed experimentation considered these factors in optimizing the process to maximize the weld tensile strength. A wide-ranging full-factorial experimental design using many levels was created for the initial testing plan. Tensile strengths obtained after welding under the various condition combinations of weld temperature and time revealed a region of higher strength values in the response surface. After the wide-range initial testing, the two control parameters, heating temperature and heating time, were ultimately set up in a focused Face Centered Cubic (FCC) Response Surface Method (RSM) testing design and the tensile strength response was then analyzed using statistical software. The results obtained indicated a strong correlation between heating time and heating temperature with strength. All welded samples in the final testing set exhibited tensile strength of over 90% base material, meeting the goal requirements. A full quadratic equation relationship for tensile strength as a function of welding time and temperature was developed and the maximum tensile strength was achieved when using 280°C for 60 seconds.

scholarly journals Synthesis and characterization of PIL/pNIPAAm hybrid hydrogels

2016 ◽  
Vol 2 (1) ◽  
pp. 1-4
Author(s):  
Sylvia Pfensig ◽  
Daniela Arbeiter ◽  
Klaus-Peter Schmitz ◽  
Niels Grabow ◽  
Thomas Eickner ◽  
...  
Keyword(s):  
Mechanical Characterization ◽  
Heating Temperature ◽  
Controlled Drug Release ◽  
Solution Temperature ◽  
Scanning Calorimetry ◽  
Critical Solution Temperature ◽  
Temperature Range ◽  
Hybrid Hydrogels ◽  
Higher Temperature

AbstractIn this study, varying amounts of NIPAAm and an ionic liquid (IL), namely 1-vinyl-3-isopropylimidazolium bromide ([ViPrIm]+[Br]−), have been used to synthesize hybrid hydrogels by radical emulsion polymerization. Amounts of 70/30%, 50/50%, 30/70%, 15/85% and 5/95% (wt/wt) of PIL/pNIPAAm were used to produce hybrid hydrogels as well as the parental hydrogels. The adhesive strength was investigated and evaluated for mechanical characterization. Thermal properties of resulting hydrogels have been investigated using differential scanning calorimetry (DSC) in a default heating temperature range (heating rate 10 K min−1). The presence of poly ionic liquids (PIL) in the polymer matrix leads to a moved LCST (lower critical solution temperature) to a higher temperature range for certain hybrid hydrogels PIL/pNIPAAm. While pNIPAAm exhibits an LCST at 33.9 ± 0.3°C, PIL/pNIPAAm 5/95% and PIL/pNIPAAm 15/85% were found to have LCSTs at 37.6 ± 0.9°C and 52 ± 2°C, respectively. This could be used for controlled drug release that goes along with increasing body temperature in response to an implantation caused infection.

scholarly journals SPECTROPHOTOMETRIC DETERMINATION OF PYROCATHECOL AND PYROGALLOL BASED ON THEIR REDOX REACTION WITH IRON(III)/PHENANTHROLINE SYSTEM

2010 ◽  
Vol 2 (3) ◽  
pp. 161-166 ◽  
Author(s):  
Mudasir Mudasir ◽  
Mugiyanti Mugiyanti ◽  
Ngatidjo Hadipranoto
Keyword(s):  
Phenolic Compounds ◽  
Redox Reaction ◽  
Heating Temperature ◽  
Heating Time ◽  
Maximum Absorption ◽  
Optimum Conditions ◽  
Phenanthroline Complex ◽  
Maximum Absorption Wavelength ◽  
Absorption Wavelength

An analytical method for the spectrophotometric determination of some phenolic compounds, i.e.: pyrocathecol and pyrogallol based on their redox reaction with iron(III)-phenanthroline complex has been developed. These two compounds, in appropriate conditions, reduce iron(III)-phenanthroline complex to yield very stable and color-intense complex of iron(II)-phenanthroline, [Fe(phen)2]2+, whose concentration is equivalent to the amount of pyrocathecol or pyrogallol in the solution, and is easily detected by spectrophotometric method. Some parameters influencing the sensitivity of the determination were optimized. These included maximum absorption wavelength, pH of the solution, time and temperature of heatingand reagent to analyte minimum mole-ratio. Using the optimum conditions obtained, the analytical performance of the method was examined and the developed method was then applied to analyzed pyrocathecol and pyrogallol contents in several river water of Yogyakarta, Indonesia. Result of the study showed that the optimum conditions for the determination of pyrocathecol are as follows: maximum absorption wavelength (lmax) at 510 nm, pH of the solution = 4, heating time = 120 min, heating temperature = 70 0C and the minimum mole ratio of reagent to analyte is 8. On the other hand, the optimum conditions for the determination of pyrogallol are as follows: maximum absorption wavelength (lmax) at 510 nm, pH of the solution = 5, heating time = 90 min, heating temperature = 90 0C and the minimum mole ratio of reagent to analyte is 7. At the corresponding conditions of analysis, calibration curves for pyrocathecol and pyrogallol are linear in the range concentration of 0.00 - 0.16 ppm and 0.00 - 0.24 ppm, respectively. The correlation coefficients for both compounds were found to be higher than 0.998 and the detection limits went down below 0.07 ppm. It has been demonstrated that the developed method can be applied for the determination of pyrocathecol and pyrogallol contents in natural samples.   Keywords: Spectrophotometry, phenolic compounds, 1,10-phenanthroline, redox reaction

scholarly journals Study on the Thermal Treatment of Nano-Ag/TiO2 Thin Film

2011 ◽  
Vol 2011 ◽  
pp. 1-5
Author(s):  
Peng Bing ◽  
Wang Jia ◽  
Chai Li-yuan ◽  
Wang Yun-yan ◽  
Mao Ai-li
Keyword(s):  
Thin Film ◽  
Methyl Orange ◽  
Thermal Treatment ◽  
Photocatalytic Degradation ◽  
Tio2 Thin Film ◽  
Heating Temperature ◽  
Antibacterial Properties ◽  
Heating Time ◽  
Degradation Rates ◽  
Temperature Heating

The photocatalytic degradation rates of methyl orange and antibacterial properties of nano-Ag/TiO2 thin film on ceramics were investigated in this study. XRD was used to detect the structure of film to clarify the impacts on the rates and properties. The effect of film layers, heating temperature, heating time, and embedding of Ag+ on the degradation rates and antibacterial properties were ascertained. The nano-Ag/TiO2 film of 3 layers with AgNO3 3% embedded and treated at 350°C for 2 h would exhibit good performance.

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