Fe70Cr10P13C7合金激光非晶化研究

Fe70Cr10P13C7是一种可形成非晶态的合金,它除具有比一般结构钢高得多的断裂强度外,还具有特别突出的耐腐蚀性能。用2～5kw连续波CO2激光在40Cr钢基体上首先获得晶态的Fe70Cr10P13C7宽带熔覆层,而后获得多道搭接的厚约0.2mm的非晶层。该非晶层动电位极化曲线表明,非晶态Fe70Cr10P13C7的耐腐蚀性高于1Cr18Ni9Ti不锈钢和加Cr的Ni-Nb非晶合金。     

均匀化退火对新型Cu-Ni-Al合金耐蚀性能的影响

在不同温度下对铸态新型Cu-Ni-Al合金进行均匀化退火,通过静态全浸试验、扫描电镜和电化学测试分析均匀化退火对新型Cu-Ni-Al合金耐蚀性能的影响。结果表明:新型Cu-Ni-Al合金的腐蚀速率随均匀化退火温度的升高而降低,在900~950℃间腐蚀速率趋向稳定;在850~950℃下均匀化退火,钝化现象明显,维钝电流密度较小,呈现良好的耐蚀性,但在850℃退火后合金的点蚀现象明显,对合金的耐蚀性不利;在900~950℃下均匀化退火后交流阻抗圆弧半径较大、电流密度较小,呈现较好的电化学特性,耐蚀性较好。     

固溶处理对Mg-Dy-Zn合金显微组织和腐蚀性能的影响

采用光学显微镜(OM)、扫描电镜(SEM)、X-射线衍射仪(XRD)、显微硬度计及电化学工作站等设备,研究了固溶处理对Mg-2Dy-0.5Zn(at%)合金显微组织及腐蚀性能的影响。结果表明,铸态合金的显微组织由α-Mg枝晶和分布在枝晶间的析出相组成,其中析出相由片层状Mg12Zn Dy相、蜂窝状Mg8Zn Dy相和少量立方体颗粒状Mg24Dy5相组成。随着固溶温度(500~540℃)和固溶时间(0~12 h)的增加,合金的析出相逐渐溶解,同时有少量颗粒状的(Mg,Zn)xDy相沿晶界析出。合金在530℃固溶8 h,析出相几乎完全固溶到α-Mg基体中,合金基体的显微硬度增加,其值达到74.74 HV0.1。此外,电化学测试结果表明,固溶态(530℃固溶8 h)合金显示出优异的耐蚀性能,其腐蚀电流和腐蚀电位分别为8.650×10-4A和-1.159 V。该优异的耐蚀性主要来自于合金元素的均匀分布,低的析出相体积分数和细小的晶粒尺寸。     

脉冲电镀Ni-W-P镀层及其耐蚀性（英文）

采用脉冲电镀法在Cu基体上制备Ni-W-P合金镀层,并通过单因素方法探讨电解液pH(1~3)、温度(40~80°C)、平均电流密度(1~7 A/dm~2)及脉冲频率(200~1000 Hz)对沉积速度、镀层结构及耐蚀性能的影响。采用扫描电子显微镜、X射线衍射和X射线能谱仪对镀层表面微观形貌、结构及元素组成进行分析。在3.5%NaCl(质量分数)溶液及土壤溶液中采用动电位极化曲线及电化学阻抗谱对镀层的耐蚀性能进行研究。结果表明:脉冲电镀Ni-W-P镀层具有良好的耐蚀性能,且脉冲电镀参数对镀层结构及耐蚀性能具有十分重要的影响。最优脉冲电镀Ni-W-P镀层参数如下:pH 2.0、温度60°C、平均电流密度4 A/dm~2、脉冲频率600 Hz。在最优脉冲电沉积参数条件下制备的Ni-W-P合金镀层具有优良的耐腐蚀性能(276.8 k?),其表面致密,无任何明显缺陷。     

表面机械研磨处理Cu-10Ni合金腐蚀性能的研究

利用表面机械研磨处理(SMAT)使Cu-10Ni合金表面纳米化.采用电化学极化曲线和电化学阻抗(EIS)技术,分别研究了原始粗晶的、经表面机械研磨处理60 min的和表面机械研磨处理60 min后200℃下退火6 h的Cu-10Ni合金在0.05 mol/L Na2SO4和0.05 mol/L H2SO4混合溶液中的电化学腐蚀行为.结果表明,表面机械研磨处理的Cu-10Ni合金腐蚀电位产生了负移,其耐腐蚀性能降低了,但其极化曲线呈现钝化特征.     

夹杂物对30Cr13和StavaxESR马氏体不锈钢耐蚀性能的影响

采用X射线衍射(XRD),扫描电镜(SEM),光电子能谱显微镜(PSEM)并结合电化学阻抗谱(EIS),动电位极化曲线测试等研究了30Cr13钢和StavaxESR钢在不同热处理状态下的微观组织、夹杂物分布及电化学腐蚀性能,并研究了碳化物及夹杂物对其耐蚀性能的影响。结果表明:经过1130℃奥氏体化处理40 min后,分布于退火态30Cr13钢和StavaxESR钢基体中的富Cr型M_(23)C_6碳化物全部固溶且在淬火时未析出,导致其耐点蚀性能提高;30Cr13钢中的夹杂物含量显著高于StavaxESR钢,且主要为(Ti,Al,Ca)N复相夹杂,与基体形成微电池,加速30Cr13钢基体溶解,导致其耐蚀性低于StavaxESR钢。     

镁锂合金表面耐蚀微弧氧化膜的研究

利用微弧氧化技术在镁锂合金的表面成功制备了微弧氧化膜.利用SEM、XRD、XPS、动电位极化和电化学交流阻抗谱对微弧氧化膜结构、相组成以及耐蚀性能进行了研究.SEM观测结果表明,氧化膜层的结构是由疏松层和致密层组成的双层结构,微弧氧化膜表面存在大量直径约2～7 μm的微孔.XRD和XPS分析表明,微弧氧化膜的主要相组成为方镁石氧化镁和无定形磷酸盐化合物.动电位极化曲线以及电化学交流阻抗谱分析表明,微弧氧化处理后镁锂合金的耐蚀性能得到显著提高.     

Fe41Co7Cr15Mo14C15B6Y2块体非晶合金在HCl溶液中的腐蚀行为

采用电化学极化曲线和电化学阻抗(EIS)测试方法研究Fe_(41)Co_7Cr_(15)Mo_(14)C_(15)B_6Y_2块体非晶合金在0.5,1,2以及4 mol/L HCl溶液中的腐蚀行为,并比较了1 mol/L HCl溶液中非晶合金和不锈钢的腐蚀行为.极化曲线测试结果表明,Fe_(41)Co_7Cr_(15)Mo_(14)C_(15)B_6Y_2块体非晶合金在各种浓度的HCl溶液中都具有很好的耐蚀性,阳极极化曲线表现出明显的钝化特征.随着HCl溶液浓度的增大,其耐蚀性能逐渐下降.在1 mol/L HCl溶液中,非晶合金的自腐蚀电位高于不锈钢,自腐蚀电流密度比不锈钢小1个数量级.EIS结果显示,在开路电位下,Fe_(41)Co_7Cr_(15)Mo_(14)C_(15)B_6Y_2非晶合金和不锈钢的Nyquist图均由单一的容抗弧构成,但非晶合金的电化学转移电阻Rt比不锈钢的大2个数量级,这一结果与极化曲线结果一致,说明非晶合金在HCl溶液中的耐蚀性能优于不锈钢.     

退火温度对磁控溅射TiN/TiCN薄膜残余应力、结构及耐蚀性能的影响

采用反应磁控溅射在AZ31合金上制备了TiN/TiCN薄膜,并对沉积后的薄膜进行真空去应力退火。分别采用X射线荧光光谱仪(XRF)、扫描电镜(SEM)、掠入射X射线衍射(GIXRD)和电化学工作站对退火前后的薄膜进行表面化学成分、形貌结构、残余应力以及耐蚀性能分析。结果表明:薄膜由FCC结构的TiCN和TiN组成。退火后,薄膜的晶粒尺寸和结晶度增大,内部残余应力显著下降,电化学腐蚀区域的Ti、C、N元素含量下降,250 ℃退火薄膜的耐蚀性能与沉积态薄膜相当,300 ℃退火后薄膜的耐蚀性能下降。     

时效处理对PH13-8Mo高强不锈钢耐局部腐蚀行为的电化学研究

采用极化曲线,电化学阻抗谱和Mott-Schottky曲线研究了不同时效温度下,PH13-8Mo高强不锈钢在3.5%NaCl溶液中形成的钝化膜性能。结果表明:时效温度对PH13-8Mo高强不锈钢耐点蚀性能有影响,具体表现为:时效时间为4 h,随时效温度升高,于480~595℃温度区间点蚀电位持续降低,温度升至621℃时,点蚀电位升高。电化学阻抗谱结果表明:随时效温度升高,钝化膜表面阻抗先增大后减小,温度升高到621℃,阻抗增大,与极化曲线测试结果一致。Mott-Schottky测试结果表明,不同时效温度下PH13-8Mo高强不锈钢表面钝化膜的致密性不同。     

Comparative study of stress corrosion cracking susceptibility of Fe18Cr10Mn- and Fe18Cr10Mn1Ni-based high nitrogen stainless steels

The stress corrosion cracking (SCC) behavior of Fe18Cr10Mn1Ni(0.3–0.8)N alloys was investigated in aqueous NaCl environment by using slow strain rate test method, and the results were compared to those of Ni-free counterparts. The addition of N tended to improve the SCC resistance of Fe18Cr10Mn- and Fe18Cr10Mn1Ni-based alloys. The alloying Ni magnified the beneficial effect of N on the SCC susceptibility and, eventually, the Fe18Cr10Mn0.8N alloy was immune to SCC in 2 M NaCl solution at 50 °C. The SCC behavior of the present alloys was found to be closely related to the repassivation tendency and the resistance to pitting corrosion.     

Towards improved integrated properties in FeCrPCB bulk metallic glasses by Cr addition

Fe-based soft-magnetic metallic glasses (MGs) of Fe_80−xCr_xP₉C₉B₂ (x = 0, 2, 5, 8 and 16 at.%) with high glass-forming ability (GFA), good soft-magnetic properties and high corrosion resistance are fabricated. With the addition of Cr to FePC-based alloys, the GFA and saturation magnetization (M_s) slightly decrease while the corrosion resistance effectively increases. The Fe–Cr–P–C–B BMGs exhibit good GFA and fully glassy rods can be produced up to 1.8 and 1.5 mm in diameter for the 2 and 5 at.% Cr added alloys, respectively. The alloys with 2 and 5 at.% Cr addition also show good soft-magnetic properties featured by high M_s of 1.16 and 1.04 T, low coercivity of 2.7 and 2.2 A/m, respectively. Besides, the corrosion behavior of the alloys was studied by immersion tests and potentiodynamic polarization measurements. It was found that the addition of Cr efficiently enhances the corrosion resistance of Fe–Cr–P–C–B alloys and the glassy alloy with 5 at.% Cr addition exhibits better corrosion resistance in comparison with the stainless steel SUS304 in 3 mass% NaCl solution. The combination of large GFA, good soft-magnetic properties, high corrosion resistance as well as low cost makes the Fe–Cr–P–C–B alloys as promising soft-magnetic and anti-corrosive materials for industrial applications.     

超级13Cr钢在不同温度NaCl溶液中的膜层电特性与腐蚀行为*

采用全浸泡腐蚀实验方法和扫描电子显微镜(SEM)、能谱仪(EDS)、X射线衍射仪(XRD)、失重法、极化曲线、交流阻抗等分析手段,对超级13Cr油管钢在不同温度NaCl溶液中的腐蚀速率、腐蚀形貌、腐蚀产物及其膜层的电性能进行了分析,研究了溶液温度对其膜层电性能和腐蚀行为的影响。结果显示:超级13Cr油管钢在温度低于80℃的NaCl溶液中具有较好的耐腐蚀性,其表面膜层具有钝化特性,温度对其腐蚀有一定程度的影响,随溶液温度的升高,钝化膜层对基体的保护作用降低,其抗腐蚀性能降低,发生腐蚀的倾向性增大,当溶液温度高于60℃时尤为显著。超级13Cr在不同温度NaCl溶液中由点蚀引发了局部腐蚀,进而导致了全面腐蚀的发生,其腐蚀产物均由Fe和Cr的氧化物组成,且表面的腐蚀产物疏松不致密。     

Corrosion Behavior of Cr, Fe and Ni Based Superalloy in Molten NaCl

熔融NaCl作为相变储热介质对容器材料具有强烈腐蚀性。通过对Cr基、Ni基和Fe基合金在850℃熔融NaCl中192 h的腐蚀实验,绘制了其腐蚀动力学曲线;利用SEM、EPMA、EDS、XRD等方法分析了腐蚀后试样横截面特征、元素分布特点及试样表面的腐蚀产物,讨论了腐蚀行为。结果表明:3种合金均满足线性腐蚀规律;Cr元素与熔融NaCl等物质反应,是导致这3种合金质量损失率增大的主要原因。Cr基合金耐蚀性最差,明显表现出晶界腐蚀特征,并且晶界为熔融NaCl渗入合金基体提供通道,促进了反应进程。Ni基合金和Fe基合金试样表面均形成了较厚的腐蚀层,为Cr2O3提供附着基体,降低了Cr元素扩散驱动力,提高了合金耐蚀性。另外,Fe基合金表面形成了尖晶石结构的腐蚀产物,进一步抑制了腐蚀过程,其耐蚀性最好。     

Influence of Cr Content on the Corrosion of Fe–Cr Alloys: The Synergistic Effect of NaCl and Water Vapor

The corrosion behavior of pure Fe and Fe–Cr alloys with different Cr content in the presence of a solid NaCl deposit and water vapor at 600°C was studied. Results indicated that the corrosion of pure Fe was severe even in air at 600°C and the scale formed on the surface was compact and uniform. However, with a solid NaCl deposit on its surface, the corrosion of pure iron in air was suppressed to some extent, but the presence of water vapor in the atmosphere causes accelerated corrosion. Under the synergistic effect of NaCl and water vapor, the corrosion of pure iron is accelerated more significantly. In contrast with the known effect of Cr content on the oxidation of Fe–Cr alloys, an increasing Cr content in Fe–Cr alloys increases the corrosion rate of the alloys under the synergistic effect of solid NaCl and water vapor. A mechanism to explain the effect of water vapor and NaCl on the corrosion of pure iron and Fe–Cr alloy is proposed.     

The corrosion behavior of Fe-based shape memory alloys

Fe-30Mn-6Si, Fe-30Mn-6Si-5Cr and Fe-13Mn-5Si-12Cr-5Ni shape memory alloys were prepared by a VIM technique. The various corrosion tests were conducted to investigate the corrosion behaviors of these alloys. Experimental results show that in 3.5% NaCl solution, the Fe-13Mn-5Si-12Cr-5Ni alloy had the best chemical corrosion resistance, whereas the Fe-30Mn-6Si-5Cr alloy was locally attacked, forming many corrosion pits after immersion test. In addition, the detachment of the corrosion product covering the Fe-30Mn-6Si alloy caused an abrupt increase in the weight loss. After 2 h of heat treatment at 1000 °C, the corrosion potential of the Fe-30Mn-6Si alloy increased due to the formation of α-ferrite, while the Fe-30Mn-6Si-5Cr alloy became more active. In the stress-corrosion cracking test, the Fe-13Mn-5Si-12Cr-5Ni alloy, having the highest fracture stress in the atmosphere among these alloys, exhibited the largest decrease in fracture stress in the saturated H₂S solution due to the existence of α-martensite.     

添加Mn和N对铁基非晶合金形成能力与腐蚀性能的影响

采用工业原料在铜模铸造的条件下制备出了ф3 mm的Fe41Co6Cr15Mo14C15B6Y2Mn1和Fe41Co6Cr15Mo14C15B6Y2N1块状非晶合金圆棒,采用X射线衍射(XRD)仪和盐酸溶液浸泡腐蚀试验分别对合金的非晶形成能力和耐蚀性进行了研究。结果表明,采用工业用料制备的铁基非晶合金中添加N时有更大的非晶形成能力和更优异的耐腐蚀性能。     

Effect of N and C on stress corrosion cracking susceptibility of austenitic Fe18Cr10Mn-based stainless steels

Stress corrosion cracking (SCC) susceptibility of austenitic Fe18Cr10Mn alloys with 0.3N, 0.6N and 0.3N0.3C was investigated in aqueous chloride environment using a slow strain rate test method. The SCC susceptibility of Fe18Cr10Mn alloys in 2 M NaCl solution at 50 °C under constant anodic potential condition decreased with increase in N content from 0.3 to 0.6 wt%, and with addition of 0.3 wt% C to the Fe18Cr10Mn0.3N alloys. The present study strongly suggested that the beneficial effects of N and C on the SCC behavior of Fe18Cr10Mn alloys would be associated with the resistance to pitting corrosion initiation and the repassivation kinetics.