Velocity hardening influence on the martensite transformation nature in constructional average alloy steel

The quantitative study of the hardening velocity influence on the α-phase morphology in 30CrNi3MoVA (0.3% C, 1% Cr,3% Ni, 1% Mo, 1% V) cast average alloy steel after gomogenization (1125℃, 13 h), normalizing (980℃, 10 h) and high tempering (660℃, 10 h. with cooling on air) is the aim of this work.     

新型马氏体耐磨钢的磨损特性研究

对自行研制的新型马氏体耐磨钢ADVANS 450W进行了900℃×0.5h油淬+300℃×2h回火处理,在MLD-10型动载磨料磨损实验机上,研究了ADVANS 450W钢在棕刚玉磨料下的冲击磨料磨损特性,并用X衍射分析仪测定了试验前后ADVANS 450W钢残余奥氏体量的变化,用扫描电镜(SEM)分析了磨损机理。结果表明:热处理后ADVANS 450W钢获得了较高的硬度,强韧性配比理想;在棕刚玉磨料下,磨损失重量随时间延长基本呈线性增长,冲击能量增加,失重量增大,磨损机理稳定,均以显微犁削为主。     

Al-RE中间合金对变形铝合金组织与性能的影响

本文以工业纯铝和混合稀土RE(Ce和La)为原料,制备出Al-8RE、Al-10RE和Al-15RE中间合金,并探讨了Al-RE中间合金对变形铝合金3102的细化机理。结果表明：Al-RE中间合金由α-Al、Al11RE3(Al11Ce3和Al11La3)、Ce和La组成,不同稀土含量Al-RE中间合金微观组织形貌不同,Al-8RE、Al-10RE和Al-15RE中间合金组织分别为亚共晶组织,伪共晶组织和过共晶组织,随稀土含量增加,Al-RE中间合金中Al11RE3相数量增多,尺寸增大;Al-RE中间合金对3102合金具有显著的细化效果,其中Al-10RE中间合金的细化效果最好;添加Al-RE中间合金可以提高产品性能,当添加10%RE时,性能提升最大。     

不锈钢和高温合金钢的切削加工性探讨

通过对不锈钢和高温合金钢切削加工性的讨论 ,找到对不锈钢和高温合金钢加工方法。解决不锈钢和高温合金钢难加工的问题     

The structural transformation in doped TiNi: dissolution of solid solutions and martensite transformations

The analysis of experiments demonstrates that in TiNi with dope d-transition elements of Ⅴ-Ⅷ subgroups the type of solid solution is determined not by the specific dope element, but by pertaining of the alloy to one of three main sections of state diagram forthe system Ti-Ni-Me.……     

The structural transformation in doped TiNi: dissolution of solid solutions and martensite transformations

The analysis of experiments demonstrates that in TiNi with dope d-transition elements of Ⅴ-Ⅷ subgroups the type of solid solution is determined not by the specific dope element, but by pertaining of the alloy to one of three main sections of state diagram forthe system Ti-Ni-Me.     

零保温奥氏体逆相变淬火温度对40Cr钢组织性能的影响

采用正交组合回归设计试验方法,研究了零保温奥氏体逆相变淬火温度对40Cr钢强度、硬度的影响,分析了其组织特征。实验表明,40Cr钢840～920 ℃零保温奥氏体逆相变淬火,可以细化奥氏体晶粒,得到细小的板条状马氏体组织。淬火温度较低时,马氏体板条间分布少量条状铁素体,随淬火温度提高铁素体逐步减少,880 ℃淬火得到全部板条状马氏体组织。在实验温度范围内,900 ℃+880 ℃两次淬火后40Cr钢的强度、硬度最高,其力学性能显著好于常规的880 ℃一次淬火。     

Effect of equal channel angular pressing (ECAP) on structure and properties of the constructional steel St3

The objective of this study was to describe two different ways for performing equal channel angular pressing of the constructional steel St3 and the relation between these two ways and steel's structure and properties.     

Effect of equal channel angular pressing (ECAP) on structure and properties of the constructional steel St3

The objective of this study was to describe two different ways for performing equal channel angular pressing of the constructional steel St3 and the relation between these two ways and steel‘s structure and properties.……     

基于模糊PID的钢丝铅浴淬火温度测控系统

阐述了基于模糊自适应PID控制的钢丝绳用钢丝铅浴淬火温度测控系统的工作原理.该系统由8031单片机作为下位机和PC机作为上位机组成.设计了温度传感器调理电路、数据采集电路、单片机系统和串行通信电路,利用Labview并结合Matlab,进行模糊推理机的结构设计,选择语言变量、隶属函数、推理规则和解模糊方法,同时进行上位机的串行通信和其他人机界面的设计.试验结果表明,该温度测控系统精度可以达到±0.8℃,可以实现比普通PID控制更高的控温精度和稳定性.     

钢管切割的半自动火焰切割机技术改造

MA Jingjing;CAI Ying     

钢纤维掺量对自密实钢管混凝土柱轴压力学性能影响研究

为提高钢管混凝土柱轴压承载力,在自密实混凝土中掺入钢纤维,研究不同钢纤维掺量对自密实钢管混凝土柱轴压力学性能的影响。通过设计正交试验,研究3组钢纤维掺量对自密实混凝土强度的影响,并为钢管混凝土钢纤维用量提供依据;对钢纤维组、普通组自密实钢管混凝土柱进行轴压试验,研究钢纤维对自密实钢管混凝土柱轴压力学性能影响;基于ABAQUS建立26组不同钢纤维掺量钢管混凝土柱模型,根据现场试验结果验证模型的正确性,分析其中6组钢纤维掺量对其轴压性能的影响,并建立不同钢纤维掺量下钢管混凝土柱轴压承载力计算公式。结果表明,2%掺量钢纤维对自密实混凝土强度增长的贡献较为显著,并能提高约4%自密实钢管混凝土柱轴压承载力,为最适宜掺量。提出考虑钢纤维掺量对钢管混凝土强度提高的计算式,与试验结果吻合良好。     

Influence of HVOF coating on the HCF of 300M low alloy steel

The ultimate methods for solving the contamination of Cr6+ is to replace the Cr electroplating with other techniques, thermal spray provides one of the best choices among those alternative techniques. The influence of coatings upon the fatigue performance of substrate, however,should be labeled as an important factor at some high level applications. The effects of both coatings manufactured by HVOF and Cr electroplating respectively on the fatigue performance of substrate are investigated in this article. These results show that the fatigue limit strength at P= 50 ,of thermal spray coating is 750 MPa in comparing with fatigue limit 726 MPa for substrate, and the fatigue life increase 25,- 150, when comparing with fatigue life of substrate at different stress levels. The fatigue life increases in the stress scope of 750-850 MPa even the area of thermal spray coating is subtracted. Cr eleetroplating coating reduces the fatigue life by 70,- 95, and the fatigue limit is only 600 MPa. Fracture analysis reveals that the main fracture is initiated at the subsurface, which is 0.2-0.5 mm away from substrate surface. The analysis also observes that the crack in the Cr electroplating propagates through the interface and finally into the substrate which hastens the formation of crack origin and the extension of crack in the substrate, however, the crack in the thermal spray coating deflects at the interface, spreads along the interface, as a result,the crack forming in the coatings has no negative influence on the main crack initiator and crack extension in the substrate.     

Influence of HVOF coating on the HCF of 300M low alloy steel

The ultimate methods for solving the contamination of Cr6+ is to replace the Cr electroplating with other techniques, thermal spray provides one of the best choices among those alternative techniques. The influence of coatings upon the fatigue performance of substrate, however,should be labeled as an important factor at some high level applications. The effects of both coatings manufactured by HVOF and Cr electroplating respectively on the fatigue performance of substrate are investigated in this article. These results show that the fatigue limit strength at P= 50 %of thermal spray coating is 750 MPa in comparing with fatigue limit 726 MPa for substrate, and the fatigue life increase 25%- 150% when comparing with fatigue life of substrate at different stress levels. The fatigue life increases in the stress scope of 750-850 MPa even the area of thermal spray coating is subtracted. Cr eleetroplating coating reduces the fatigue life by 70%- 95% and the fatigue limit is only 600 MPa. Fracture analysis reveals that the main fracture is initiated at the subsurface, which is 0.2-0.5 mm away from substrate surface. The analysis also observes that the crack in the Cr electroplating propagates through the interface and finally into the substrate which hastens the formation of crack origin and the extension of crack in the substrate, however, the crack in the thermal spray coating deflects at the interface, spreads along the interface, as a result,the crack forming in the coatings has no negative influence on the main crack initiator and crack extension in the substrate.     

Influence of HVOF coating on the HCF of 300M low alloy steel

1IntroductionLanding gear is easily worn due to its action with ground during landing and takeoff,and traditionalabrasive-resistance methodis the Cr electroplating technology.Cr is deposited owing to the oriented move-ment of Cr2O7-to the cathode of D.C.where electrochemical reactions take place.The technology is fea-tured as si mplicity,lowcost,high hardness,good abrasion-and corrosion-resistance andis widely appliedin many industries.However,Cr electroplating technique will let off carcin…     

硼元素对钢砂(丸)性能的影响

采用离心喷溅式方法制备钢砂丸,对钢砂丸的耐磨损性能、显微硬度及显微组织等进行了测试.结果表明,当钢砂中硼质量分数高于0.03%时,随着钢砂丸硼含量的增加,钢砂丸的组织变粗大,晶界变明显,耐磨性变差.硼含量为0.03%的钢砂丸的硬度和耐磨性较高、磨损后粒度分布较好、外观圆整率高及空心率低.