B30MnSi钢的动态再结晶行为

采用Gleeble1500热模拟试验机对B30MnSi钢(%:0.32C,1.04Mn,0.85Si,0.019P,0.009S)进行变形温度为850～1000℃,应变速度为0.1～101/s的压缩变形试验,以研究该钢的动态再结晶规律。并通过回归分析得出峰值应力σm,应变εp,动态再结晶临界应变εc与温度补偿变形速率因子Z之间关系式为σm=16.689Ln(Z)-347.41;εp=0.0474Ln(Z)-1.1023;εc≈0.0393Ln(Z)-0.915。     

钛合金表面硬化与固体润滑处理层的电化学腐蚀行为研究

分别利用等离子氮化技术和离子束增强沉积(IBED)技术使钛合金表面获得硬质抗磨层和MoS2，MoS2-Ti固体润滑膜层。通过电化学测试技术研究了膜层和钛合金基材在含Cl^-介质中的抗蚀性能和接触腐蚀敏感性：研究结果表明：Ti与MoS2的复合改善了MoS2膜的环境适应性，MoS2—17Ti复合膜层与钛合会接触相容；IBED TiN较钛合金电化学活性低，阳极极化行为与Ti6Al4V合金相近，与钛合金基体间电偶腐蚀敏感性低；钛合金等离子氮化处理层在NaCl水溶液中无论处于自然腐蚀电位还上弱阳极极化状态，均较钛合金电化学活性低，且与钛合金基体间电偶腐蚀敏感性低。     

钒对30MnSi钢热变形行为的影响

通过对30MnSi和30MnSiV两种钢在Gleeble-1500热模拟试验机上的高温压缩变形实验，分析了不同变形条件下微合金元素钒对变形抗力的影响，通过试验数据的计算可知，30MnSiV钢的再结晶激活能比30MnSi钢大6.7%左右。     

30CrMnMo钢调质Q125钢级套管的工艺研究

文章采用包钢现有钢种30CrMnMo进行了Q125钢级石油套管的热处理工艺研究,结果表明：该钢在9004-10℃保温40～50min水冷,630±10℃回火70～80min后有较好的强度和韧性,力学性能符合APISPEC5CT对Q125套管的性能要求。     

热处理工艺制度对30MnCr22钢力学性能的影响

文章通过对不同淬火温度、回火温度以及回火保温时间下的30MnCr22钢调质生产的P110钢级石油套管力学性能的实验室研究,得出热处理对30MnCr22钢力学性能的影响趋势,筛选出最佳的热处理制度,应用于当前工业化生产中。     

热处理工艺对30MnSi PC钢棒力学性能的影响

针对30MnSi 预应力混凝土用钢棒(简称PC钢棒)在实际生产中抗延迟断裂性能差、力学性能不稳、屈强比高等问题,从生产PC钢棒的技术关键热处理制度入手, 通过调质处理得到回火屈(索)氏体组织,分别绘出了淬火温度、回火温度与抗拉强度、伸长率、屈强比的关系曲线.系统地研究了热处理工艺参数对钢棒的组织及强韧性的影响规律并进行了理论分析.摸索出了生产30MnSi PC钢棒的合理工艺制度:当加热时间一定时,淬火温度920～960 ℃,回火温度控制在390～430 ℃时,能获得较好的综合力学性能.     

钇对17CrMoV钢离子氮化特性的影响及催渗机理的探讨

本研究采用金相显微镜、透射电子显微镜、显微硬度计等仪器分析对比了１７ＣｒＭｏＶＹ和１７ＣｒＭｏＶ钢离子氮化层特性，探讨了钇加速离子氮化的机理，提出了钢中钇催渗的“气团─通道”模型。研究结果表明：钇显著提高渗层深度与硬度；钇影响钢的组织转变，提高渗层氮浓度，使氮化物更易于析出；大量弥散、细小氮化物的快速析出又为氮的进一步扩散提供了更多的扩散通道，加快氮的扩散。     

高速列车车轴钢30NiCrMoV12的热变形行为

通过Φ250 mm锻件切取的试样在Gleeble-3500热模拟机于850~1150℃以应变速率0.01~10s^-1对高速列车车轴钢30NiCrMoV12(/%:0.26C,0.33Si,0.62Mn,3.01Ni,0.82Cr,0.56Mo,0.10V)进行了热压缩试验。研究了车轴钢在热变形过程中奥氏体变形行为及再结晶规律,确定了车轴钢的热变形方程,建立应变量ε为0.5和0.9的热加工图。结果表明,在应变速率一定时,温度越高,变形量越大,则越有利于动态再结晶的发生;随着温度升高以及应变速率降低,能量耗散效率η逐渐升高;当真应变0.5,温度1100℃,应变速率0.01 s^-1时,变形能量耗散效率达到最大值0.41。该车轴钢在1000~1150℃,应变速率0.01~1.0s^-1时,具有较好的可锻性。     

Tribological Properties of CrN Coated H13 Grade Tool Steel简

The characteristics of CrN coated martensitic H13 grade tool steels were studied. CrN coatings were depos- ited by the arc physical vapor deposition （PVD） before and after the pulse plasma nitriding of the samples. The PVD and plasma nitriding techniques were applied in relevant workshops by following the commercial practice parameters. Experimental results showed that CrN coating deposited on the nitrided surfaces exhibited superior scratch and wear resistances as compared to that deposited on the original martensitic surface.     

Wear Behavior and Mechanism of a Sliding Pair of 0.1C-3Cr-2W-V Nitrided Steel Rubbing against an Aluminum Bronze Alloy

Wear behavior and mechanism of plasma nitrided steel oscillating against a heat-treated and an untreated aluminum bronze alloy were investigated using an Optimol SRV tribometer.The influence of heat treatment on the mechanical properties of the alloy was evaluated.Furthermore,the wear debris was also examined to understand the wear mechanisms.The results show that a 220-230μm nitrided layer,which was harder than the substrate,was obtained on the steel surface.The tensile strength and hardness of the alloy are found to be significantly improved by the heat treatment associated with low impact toughness.The heat treatment of the alloy did not obviously decrease the friction coefficient of the nitrided steel-bronze couple.However,the wear loss of the nitrided steel increased when it mated with the treated bronze by a severe three-body abrasion.The nitrided steel was mainly damaged by fatigue spalling.Under plane contact conditions,the wear debris was mainly generated from the bronze part and can escape from the interface before being oxidized,leading to the phase structure of all the debris being copper rather than copper oxides.     

Influence of Shallow and Deep Cryogenic Treatment on Tribological Behavior of En 19 Steel

 The influence of cryogenic treatment on the wear resistance of En 19 steel was studied. Furthermore, a comparative analysis on the effect of Deep Cryogenic Treatment (DCT, -196 ℃×24 h), Shallow Cryogenic Treatment (SCT, -80 ℃×5 h) and Conventional Heat Treatment (CHT) was done through dry sliding wear testing. The microstructures of CHT, SCT and DCT samples were also examined through scanning electron microscopy. The results indicated that the wear resistance of shallow and deep cryogenically treated samples is higher when compared to that of conventionally treated samples. X-ray diffraction pattern revealed that the transformation of retained austenite into martensite is responsible for the wear resistance improvement.     

2507超级双相不锈钢的热变形行为

用MMS-200热模拟实验机对2507超级双相不锈钢(/%:0.022C、0.58Si、25.35Cr、7.17Ni、4.05Mo、0.28N)12 mm热轧板在1 000～1150℃、应变速率0.01～10s^-1下进行了热压缩实验。实验结果表明,在应变速率一定的条件下,变形温度越高,2507超级双相不锈钢峰值应力越低;在变形温度一定的条件下,峰值应力随着应变速率的增加而增加。根据热变形方程计算得到压缩变形时的平均表观应力指数n=3.25,热变形激活能Q=460kJ/mol。基于实验数据构建了2507超级双相不锈钢在相应变形条件下的热变形方程。     

2205双相不锈钢的高温变形行为研究

在Gleeble-1500热模拟试验机上进行热-力模拟试验,得到实验数据并分析试样的热塑性、变形抗力,并利用金相显微镜对其进行金相组织的分析。在950~1 200℃温度区间进行高温拉伸试验,绘制出样品的热塑性曲线与热强度曲线,通过热塑性曲线说明在950~1 200℃范围内具有良好的塑性,通过热强度曲线可以观察到屈服强度随温度的升高而降低;在变形温度为950~1 200℃,应变速率为0.1,1,5和10 s-1时进行高温压缩试验,绘制出真应力-应变曲线和变形抗力曲线,结果显示,变形抗力随应变量的增大而迅速达到最大值,而后趋于平缓,随着温度的升高,变形抗力呈下降的趋势。     

Plasma Nitriding of 722M24 Steel with Pure Lanthanum, Cerium and Neodymium as Sputter Sources

Ｓｉｎｃｅｔｈｅｉｎｉｔｉａｌｒｅｐｏｒｔｉｎｔｈｅｅａｒｌｙ 1 980ｓｔｈａｔｒａｒｅｅａｒｔｈａｄｄｉｔｉｏｎｈａｓａｃａｔａｌｙｔｉｃｅｆｆｅｃｔｏｎｔｈｅｇａｓｃａｒｂｏｎｉｔｒｉｄｉｎｇｐｒｏｃｅｓｓｏｆｓｔｅｅｌｓ[1] ,ａｌａｒｇｅａｍｏｕｎｔｏｆｗｏｒｋｈａｓｂｅｅｎｃｏｎｄｕｃｔｅｄｔｏｉｎ ｖｅｓｔｉｇａｔｅｔｈｅｉｎｆｌｕｅｎｃｅｏｆｒａｒｅｅａｒｔｈａｄｄｉｔｉｏｎｓｏｎｖａｒｉｏｕｓｔｈｅｒｍｏｃｈｅｍｉｃａｌｐｒｏｃｅｓｓｅｓ[2～ 8] .Ｉｔｈａｓｂｅｅｎｅｓｔａｂｌｉｓｈｅ…     

双相不锈钢高温微观变形行为

 利用共聚焦激光扫描高温显微镜(CSLM)等设备对双相不锈钢的高温拉伸变形行为进行了研究,分析了双相不锈钢的热塑性变形机理,得出影响双相不锈钢热塑性的主要因素有：相界结合力、组织形貌和两相力学性能的差异。指出在双相不锈钢热加工时,增强相界结合力、优化组织形貌或减小两相力学性能差异,可有效改善双相不锈钢的热塑性。     

轴承钢凝固过程TiN析出的研究

对轴承钢连铸坯中夹杂物进行了检测,发现铸坯中存在大尺寸的Ti N夹杂物。从热力学和动力学方面研究了凝固过程选分结晶对Ti N夹杂物析出的影响。热力学分析表明,液相线温度以上不会有Ti N析出;凝固过程由于凝固前沿Ti、N富集,当凝固率达到0.65~0.75后会有Ti N析出;降低Ti、N含量可推迟Ti N的析出,减小Ti N夹杂的尺寸和数量。动力学分析表明,随着冷却速度的降低,凝固过程Ti N夹杂物的尺寸显著降低,当冷速高于50K/s时,Ti N的理论半径为2.4μm,当冷速低于5 K/s时,Ti N的理论半径在7.6μm以上;完全凝固后铸坯冷却过程析出的Ti N为纳米级。实际铸坯表层未发现等效半径大于2.5μm的Ti N,1/4和中心处观察到的最大Ti N等效半径分别为6.77μm和8.46μm,这表明铸坯中大尺寸Ti N夹杂物是在凝固过程析出的。     

40Cr钢的离子渗氮层结构与抗冲蚀行为

研究了在含沙泥浆中不同冲击速度（１．４,２．４,３．６和５ｍ／ｓ）下４０Ｃｒ钢的调质与离子渗氮试样的冲蚀行为。试验结果表明：调质试样的冲蚀失重明显高于离子渗氮试样,并且其冲蚀失重随冲击速度的增加发生明显变化,表面呈现明显凹坑;而离子渗氮试样的冲蚀失重极少,并且其冲蚀失重随冲击速度增加变化不大,表面损伤不明显。这说明离子渗氮后４０Ｃｒ钢表面形成的坚硬氮化物结构具有优良的抗冲蚀能力     

Microstructure Evolution and Mechanical Behavior of a CMnSiAl TRIP Steel Subjected to Partial Austenitization Along with Quenching and Partitioning Treatment

The present study investigated the microstructure evolution and mechanical behavior in a low carbon CMnSiAl transformation-induced plasticity (TRIP) steel, which was subjected to a partial austenitization at 1183 K (910 °C) followed by one-step quenching and partitioning (Q&P) treatment at different isothermal holding temperatures of [533 K to 593 K (260 °C to 320 °C)]. This thermal treatment led to the formation of a multi-phase microstructure consisting of ferrite, tempered martensite, bainitic ferrite, fresh martensite, and retained austenite, offering a superior work-hardening behavior compared with the dual-phase microstructure (i.e., ferrite and martensite) formed after partial austenitization followed by water quenching. The carbon enrichment in retained austenite was related to not only the carbon partitioning during the isothermal holding process, but also the carbon enrichment during the partial austenitization and rapid cooling processes, which has broadened our knowledge of carbon partitioning mechanism in conventional Q&P process.