热连轧工艺对GH4648合金棒材组织与性能的影响

研究了连轧生产线生产的GH4648合金热轧棒材的组织与性能.采用热连轧过程的自动化控制系统调整棒材的轧制速度、保持稳定的终轧温度,从而获得晶粒组织均匀、α-Cr相形态与分布合理的热轧棒材.与传统的横列式轧机相比,工艺更稳定、可控,热轧棒材的组织稳定、性能提高.     

微量元素Sb对AZ31合金组织与蠕变性能的影响

通过蠕变曲线的测定、x-射线衍射分析及SEM、TEM形貌观察，研究了微量元素Sb对AZ31合金的组织结构及蠕变性能的影响.结果表明：在AZ31合金中加入元素Sb后，有效降低了合金应变量及稳态应变速率.当加入0.84% Sb后，使合金的稳态蠕变速率降低了2.5倍，显著提高了合金的蠕变寿命.高体积分数(～20%)第二相的存在，特别是合金中弥散分布高熔点的Mg₃Sb₂相，在高温蠕变期间可有效地阻碍位错运动，也是该合金具有较好蠕变抗力的主要原因.     

Sn对AX55铸造合金组织与蠕变性能的影响

为了提高Mg-5Al-5Ca(AX55)铸造镁合金基体组织和共晶组织的耐热性能,以Sn为变量设计了AX55-x Sn(x=0,0. 5,1. 0,1. 5)合金,研究了T61和T62对合金组织、硬度与蠕变性能的影响.结果表明,随着Sn含量的增加,合金基体中析出的Al2Ca相增多,使得α-M g基体得到强化.在共晶骨架相附近析出的CaMgSn相可使共晶组织得到强化.在175℃/70 MPa蠕变100 h条件下,AX55-x Sn合金的最小蠕变速率和蠕变总量随Sn含量的提高而降低. AX55-1. 5Sn合金性能最佳,且其最小蠕变速率为5. 21×10-8s-1,100 h总蠕变量为0. 065%.相比T61,T62能够提高AX55-x Sn合金的基体硬度和蠕变性能.     

热连轧GH4169合金组织结构与蠕变变形及断裂机制

为了研究直接时效对热连轧GH4169合金组织结构及蠕变行为的影响,通过对热连轧合金直接时效、蠕变性能测试和组织形貌观察,分析了热连轧直接时效合金的组织结构与蠕变变形及断裂机制.结果表明：经直接时效热连轧合金组织由细小晶粒构成,且具有明显的孪晶特征,细小γ″相在合金中弥散析出;在蠕变期间,合金的变形特征是形成三取向孪晶变形和位错在基体中发生单双取向滑移、起形变强化作用、使合金具有较高蠕变抗力和较长蠕变寿命的原因;随着蠕变的进行,位错逐渐在晶界处堆积并产生应力集中,促使裂纹在晶界处萌生;在蠕变后期,合金的蠕变断裂机制表现为裂纹沿晶界扩展并发生断裂.     

成分和工艺对Nb＋Ti-IF钢组织和性能的影响

以Nb Ti-IF钢为研究材料,进行了实验分析,根据实验结果,从化学成分、卷曲温度、冷轧压下率、退火工艺等方面分析了该材料的组织与性能.     

枝晶间距对镍基单晶合金蠕变性能的影响

为了研究枝晶间距对镍基单晶合金组织与蠕变性能的影响,采用不同抽拉速率制备出两种不同枝晶间距的单晶镍基合金.通过蠕变性能测试及组织形貌观察,研究了枝晶间距对合金成分偏析及蠕变性能的影响.结果表明,随着合金枝晶间距的减小,元素成分偏析程度降低,且在相同热处理条件下,枝晶间距较小的合金具有较好的蠕变性能.合金在稳态蠕变期间的变形机制是位错攀移越过筏状γ′相,而蠕变后期的变形机制是位错在基体中滑移和切入筏状γ′相.蠕变断裂后,在试样不同区域筏状γ′相具有不同的形貌,在远离断口区域,筏状γ′相与应力轴方向垂直,而在近断口区域,筏状γ′相尺寸及扭曲程度均增加.     

Nb对ZG1Cr10MoNiVNbN钢的组织和性能的影响

为了研究Nb合金元素对ZG1Cr10MoNiVNbN牌号的耐热耐腐蚀钢组织和性能的影响,通过金相观察、拉伸、冲击试验和电化学腐蚀,得到Nb元素对此牌号钢力学性能和耐腐蚀性能的影响规律。结果表明:当Nb元素质量分数为0.15%时,钢中的板条状组织更加细小,碳化物分布也更加均匀,在力学性能方面,Nb量为0.15%的钢的屈服、抗拉强度为864.1、985.7 MPa,伸长率和冲击功分别为14.4%和26.9 J,在耐腐蚀性能方面,维顿电流密度和腐蚀电位分别为3.125 4E-7 A/cm~2,-0.161 03 V。     

时效对Ti3Al—Nb合金显微组织与拉伸性能的影响,

研究了Ｔｉ３Ａｌ－Ｎｂ（Ｔｉ－２４Ａｌ－１４Ｎｂ－３Ｖ－０．５Ｍｏ）ａｔ％）合金时效过程中组织与性能的变化，结果表明，合金经α２＋β两相区１０００℃ｌｔ／ＷＱ固溶处理后，分别在６５０、７５０和８５０℃哩效２４ｈ空冷，会使其析出二次针状α２相和大量“Ｏ”相，随着时效温度的升高，实姓α２相长大，二次针状α２相和“Ｏ”相球化。“Ｏ”相除以块状形式存在于初生α２相周围外，还成片分布于初生α２相内部。时效温     

家族企业的组织结构与组织效能

组织结构、组织成员的意愿及其与外部社会的交流,对组织的效能有直接的影响。组织效能是决定该组织的生存与发展一个重要依据。家族企业是一种企业组织形式,通过对家族企业组织结构的探讨,分析了家族企业的组织效能。在共同利益的前提下,家族企业良好的合作、协助意愿和更多的信息交流机会,可使家族企业成为组织效能极高的组织;反之,则会导致家族企业的组织效能低下。     

猪、羊皮成品革的组织结构与性能的关系探讨

用硫酸耐尔兰染色法制备不同手感猪、羊皮成品革组织切片，在多媒体显微镜下观察其组织结构，分析了其组织结构与性能的关系。     

Microstructures and mechanical properties of Mg-Ce-Zn-Zr wrought alloy

Microstructures and mechanical properties of Mg-2.0 ?-0.7 % Zn-0.7% Zr alloy were studied. The results of scanning electron microscopy show that Mg12 Ce phase mainly distributes at the grain boundaries. The fine Mg12 Ce phase can apparently elevate recrystallization temperature by preventing the grain boundary migration. No dynamic recrystallization occurs during the hot-extrusion. The mechanical properties of as extruded specimens are σb=278.5MPa, δ=12.0%, while those of the specimens annealed at 250℃ for 100 h are σb=272.6 MPa, δ=11.3%, which indicate that the alloy has good mechanical properties at room temperature.     

Modeling of metadynamic recrystallization kinetics after hot deformation of low-alloy steel Q345B

Based on the steady-state strain measured by single-pass hot compression tests, the method by a double-pass hot compression testing was developed to measure the metadynamic-recrystallization kinetics. The metadynamic recrystallization behavior of low-alloy steel Q345B during hot compression deformation was investigated in the temperature range of 1 000–1 100 °C, the strain rate range of 0.01–0.10 s⁻¹ and the interpass time range of 0.5–50 s on a Gleeble-3500 thermo-simulation machine. The results show that metadynamic recrystallization during the interpass time can be observed. As the deformation temperature and strain rate increase, softening caused by metadynamic recrystallization is obvious. According to the data of thermo-simulation, the metadynamic recrystallization activation energy is obtained to be Q _md=100.674 kJ/mol and metadynamic recrystallization kinetics model is set up. Finally, the error analysis of metadynamic recrystallization kinetics model proves that the model has high accuracy (correlation coefficient R=0.988 6).     

Hot deformation behavior of FGH96 superalloys

1. Introduction Precipitation-hardened nickel-based superalloys have been widely used as high-temperature structural materials in gas turbine engine applications for more than 50 years. Because powder metallurgy (P/M) process produces a fine, homogenous a…     

Hot deformation behavior of Super304H austenitic heat resistant steel

The hot compression tests of Super304H austenitic heat resistant steel were carried out at 800-1200℃and 0.005-5 s~(-1) using a Gleeble 3500 thermal-mechanical simulator,and its deformation behavior was analyzed.The results show that the flow stress of Super304H steel decreases with the decrease of strain rate and the increase of deformation temperature;the hot deformation activation energy of the steel is 485 kJ/mol.The hot deformation equation and the relationship between the peak stress and the deforma...     

Microstructure homogenization control of Nb-bearing X65 pipeline steel by the CSP process

In order to get the controlled methods of microstructure homogenization and high strengthening-toughening combination by compact strip production (CSP) rolling,the dynamic recrystallization characteristics of each pass were obtained during CSP rolling using a Gleeble-1500 thermal mechanical simulator.Then,the CSP process was simulated by laboratory rolling experiment.Through thermal mechanical simulation experiment and laboratory rolling experiment,a design idea of Nb-bearing pipeline steel by CSP can be ob...     

Static and dynamic finite element analysis of 304 stainless steel rod and wire hot continuous rolling process

Three-dimensional finite element models were developed to analyze 304 stainless steel rod and wire hot continuous rolling process with the help of MSC.Marc software. The entire 30-pass deformation process and the actual parameters of production line were taken into account. Static and dynamic procedures were used to study the continuous rolling process with the aid of the thermo-mechanical coupled FEM of elastic-plasticity. The properties of billets, such as deformation, temperature field and rolling force, were mainly discussed. The simulation results of temperature agree well with the measured values. Comparisons of the analysis results obtained using static implicit method and dynamic implicit method were presented. It is shown that static implicit procedure is more accurate than dynamic implicit procedure and is able to simulate the rolling process with a lower speed, such as a roughing mill. Whereas, dynamic analysis shows a higher efficiency than static analysis and is fit for simulating the rolling process with a higher speed, such as a finishing mill.     

预先再结晶对冷轧双相钢组织性能的影响

通过实验研究了预先再结晶对冷轧双相钢组织性能的影响。首先通过研究再结晶演变规律确定了预先再结晶的温度和时间分别为700℃保温30s;另外,通过奥氏体形成动力学及相变点检测确定两相区退火工艺参数;最后分析了预先再结晶对冷轧双相钢组织性能的影响。实验表明：冷轧钢板经T=700％,t=308预先再结晶处理后,迅速升温进入双相区热处理可以较好的消除了条带状组织,得到均匀的F＋M双相组织,其塑性有了较大幅度的提高,抗拉强度略有上升。     

热轧温度对Zr-4合金力学性能和耐腐蚀性能的影响

热加工工艺对Zr-4合金板材的力学性能及耐腐蚀性能有极其重要的影响,将Zr-4合金板在800℃和960℃两种温度条件下热轧开坯至2.4 mm厚度,经退火后冷轧加工成为1.2 mm和0.6 mm厚的带材,研究了热轧温度对Zr-4合金板材室温力学性能和腐蚀性能的影响.研究表明,800℃热轧后所制备板材的强度低于960℃热轧后的板材,而延伸率大于960℃热轧后的板材;800℃热轧所制备的0.6 mm厚的Zr-4合金板材的腐蚀性能优于960℃热轧所制备的板材.由研究结果可得：Zr-4合金板材在实际生产过程中需合理地控制热加工温度.