共查询到20条相似文献,搜索用时 0 毫秒
1.
单庆林贾刘兵彭国仲王皓张丙龙王胜东 《连铸》2017,36(1):30-34
针对连铸过程中产生的非稳态坯,通过夹杂物分析和氮氧分析,掌握各类非稳态因素对铸坯质量的定量影响。从夹杂物数量密度对夹杂物进行了分类,得到铸坯质量优先级顺序:正常坯>尾坯>换水口坯>头坯。对非稳态坯进行有针对性地工艺技术攻关,采用中包充氩技术、快涨拉速技术,头坯头部全氧质量分数由研发前的7.1×10-5降低至当前的4.0×10-5;通过快降、快涨拉速协同控制技术、接痕控制技术,换水口坯大型夹杂物数量(大于50 μm)由研发前的0.8 个/cm2降至0.4 个/cm2;采用“一键式”拉速控制技术、二冷水幅切控制技术和轻压下时间控制技术,尾坯的中心疏松得到了显著改善。 相似文献
2.
3.
Jong-ha Park Soo-sang Park Xue-feng Han Kyung-woo Yi 《Metals and Materials International》2016,22(1):118-128
To understand complex behavior in the smelting furnace of Mitsubishi continuous process for copper refining, comprehensive 3-D numerical simulation and field experiment were performed. The numerical simulation results showed that strong and complex velocity fields of gas, matte and slag were generated in the furnace and large amounts of matte and slag were splashed into the gas area. Temperature measurements at the lance during field operation revealed that wide range of temperature variation appeared depending on the injection condition of concentrates. Numerical simulation results provided good agreements with experiments results and showed that the chemical reaction induces temperature increase during gas injection period. On the other hand, lance temperature is decreasing because of cold concentrates during gas and particles injection period. From the FFT analysis results, the fluctuations of matte and slag volume fraction near the lance induce temperature fluctuations of the lance. Through these experimental and simulation results, it was revealed that the lances in the smelting furnace were exposed to severe conditions such as high temperature, repeated large temperature change and cyclic change of large temperature gradient across the thickness. 相似文献
4.
The aim of the present work was to utilize a new systematic mathematical-informational approach based on informational macrodynamics
(IMD) to model and optimize the casting process, taking as an example horizontal continuous casting (HCC). The IMD model takes
into account the interrelated thermal, diffusion, kinetic, hydrodynamic, and mechanical effects that are essential for the
given casting process. The optimum technological process parameters are determined by the simultaneous solution of problems
of identification and optimal control. The control functions of the synthesized optimal model are found from the extremum
of the entropy functional having a particular sense of an integrated assessment of the continuous cast bar physicochemical
properties. For the physical system considered, the IMD structures of the optimal model are connected with controllable equations
of nonequilibrium thermodynamics. This approach was applied to the HCC of ductile iron, and the results were compared with
experimental data and numerical simulation. Good agreement was confirmed between the predicted and practical data, as well
as between new and traditional methods. 相似文献
5.
Stability condition of semisolid continuous casting process 总被引:2,自引:0,他引:2
1 INTRODUCTIONThesemisolidcontinuouscasting ,SSCCforshort,isanew processwithlowconsumptionandhighproductivityto producehigh qualitybilletforsemisolidalloysforming .However ,thebreakoutandbreakageoftenoccurintheprocessbecauseoflackingsufficientresearchonth… 相似文献
6.
Numerical simulation of semisolid continuous casting process 总被引:1,自引:0,他引:1
1 INTRODUCTIONSemisolidcontinuouscasting(SCC)isstillintheexperimentalstudystageinChina[1~ 3] .Therefore ,manyproblemsareneededtobeexploredcontinuous ly .Amongthem ,thebreakageandbreakoutarethekeyblockstolimittheindustrialapplicationoftheprocess.Becauseoftheco… 相似文献
7.
连续挤压成形过程的计算机仿真 总被引:8,自引:0,他引:8
在分析连续挤压技术特点的基础上,采用刚粘塑性有限元模型,建立了连续挤压的计算机仿真模型,包括几何模型、材料模型、塑性力学模型、摩擦力学模型和热力耦合模型;组建了一个有关连续挤压的计算机仿真系统,对连续挤压的成形过程进行了计算机仿真,得出了有关连续挤压全过程的应力场、应变场和温度场. 相似文献
8.
9.
PC与三菱FX2N型PLC串口通信的实现 总被引:8,自引:0,他引:8
本文介绍了VB60通信控件的特性及其用途,并阐述了FX系列PLC编程口通信协议,最后重点给出PC机与三菱FX2N型PLC串口通信的实现方法。 相似文献
10.
On some aspects of gas dynamics of the cold spray process 总被引:1,自引:0,他引:1
V. F. Kosarev S. V. Klinkov A. P. Alkhimov A. N. Papyrin 《Journal of Thermal Spray Technology》2003,12(2):265-281
This paper presents an overview of results of recent studies conducted at the Institute of Theoretical and Applied Mechanics
of the Siberian Division of the Russian Academy of Science in the field of gas dynamics and heat transfer of the supersonic
air jet under conditions typically used in the cold spray process. These studies are related to various aspects of the problem
including a flow in the nozzle and the outflow of the jet, as well as effects of the interaction of the jet with a flat obstacle.
They are conducted with a supersonic nozzle with a rectangular section at the exit with a Mach number M
0 between 2 and 3.5. The gas flow in the nozzle is theoretically and experimentally studied. It is shown that the boundary
layer on the walls of the nozzle affects significantly the flow parameters (for example, Mach number M, pressure p, temperature T, and density ρ of the gas). A method of calculation of the gas parameters in the flow core of the nozzle is suggested, and
it is shown that they depend mainly on the ratio of the nozzle width to its length. The results of the investigation of the
supersonic air jets with stagnation temperature ranging from 300–600 K flowing in the atmosphere are presented. The corresponding
dimensions of the jets, profiles, and axial distributions of the gas parameters are obtained. The interactions of the supersonic
jet with the flat obstacle are studied. Self-similarity of the distribution of the pressure and of the Mach number on the
obstacle surface is shown for the jets with various values of the Mach number and the angle of impingement. The oscillation
regimen of the jet impingement, as well as a compressed layer structure is observed with the aid of a Schliren visualization
technique. Some problems of heat exchange of the jets with the obstacle are considered. Distributions of stagnation temperature
and heat exchange coefficient in the near-wall jet are obtained. The temperature of the obstacle for the stationary case is
calculated, and it is shown that for heat conductive materials the surface temperature is lower than the stagnation temperature
due to the redistribution of heat inside of the substrate. 相似文献
11.
本文对连铸结晶器内的铸坯早期凝固过程做了热力耦合分析 ,该分析过程不涉及具体的连铸形式 ,因而适用范围广。根据所建立的数学模型编制了有限元程序 ,并以圆坯连铸过程为例进行了计算 相似文献
12.
13.
14.
15.
16.
本文从生产效率、能耗、产品质量等方面对采用连续挤压法和铸坯轧制法加工KFC引线框架带材进行比较,得出采用连续挤压法加工KFC带材在生产效率和质量稳定性方面比传统的铸坯轧制法有较大提高。 相似文献
17.
Results of a theoretical and experimental study of the process of continuous forming of nanocrystalline powder materials for making long-length articles with nanocrystalline structure are presented. The laws relating the energy and force parameters of the process and the geometric parameters of the tool are determined. Relations for minimizing the energy and force parameters of the process by optimizing the geometric parameters of the tool are obtained. 相似文献
18.
In order to improve the strip quality of continuous roll-casting process (CRP) of aluminum alloy, the investigations of the flow behavior within the metal pool, the heat transfer condition between roll and strip, the pouring temperature of molten alloy, the roll-casting speed and the control of the position of solidification final point are important. The finite volume method was applied to the analysis of the continuous roll-casting process. A two-dimensional incompressible non-Newtonian fluid flow with heat transfer was considered, which was described by the continuity equation, the Navier-Stokes equation and the energy equation. With this mathematical model, the flow patterns, temperature fields and solid fraction distributions in the metal pool between two rolls were simulated. From the calculated results, the effects of technical parameters to the position of solidification final point are obtained. The simulated results show that the roll-casting speed and pouring temperature have an enormous effect on the temperature distribution and the position of solidification final point. 相似文献
19.
20.
对TA15钛合金高温变形机制进行了Gleeble热模拟试验,并利用试验结果设计了在850~950 ℃范围,直径为20 mm 的TA15钛合金小规格棒材的新型热连轧生产工艺.试验结果表明:采用合适的热连轧工艺,TA15钛合金小规格棒材的组织和性能与传统的横列式轧制棒材的相当,均满足相应的技术要求. 相似文献