热处理工艺对2205双相不锈钢耐蚀性能的影响

对2205双相不锈钢采用不同温度进行热处理,然后用光学显微镜和电子扫描电镜观察其在0.33mol/L FeCl3+0.05 mol/L HCl溶液中腐蚀后的形貌;测试其显微硬度的变化、在沸腾的65%的硝酸溶液中浸蚀24 h的腐蚀速率和在25℃的3.5%NaCl溶液中的点蚀电位。研究表明:2205双相不锈钢在750~900℃保温4h有σ相析出,材料的显微硬度增大。同时随着热处理温度的升高,2205双相不锈钢的点蚀电位降低,腐蚀速率增大。     

不同热处理条件下双相钢的磨损腐蚀

采用失重法、极化曲线法对不同热处理条件下双相钢 在流动的35% NaCl中性盐水中的磨损腐蚀规律及机理进行了探讨.结果表明，随着流速的 增大，不同热处理的双相钢腐蚀速度均增大，并存在一个使腐蚀速度急剧上升的临界流速值 ；流速相同时，经1050℃固溶后500℃2 h时效强化的双相钢耐蚀性最好.双相钢的腐蚀主要 受阳极的自钝化控制.     

热处理对SLM18Ni300马氏体时效钢组织及腐蚀性能的影响

目的探究热处理对激光选区熔化(SelectiveLaserMelting,SLM)成形18Ni300马氏体时效钢组织和耐腐蚀性能的影响。方法利用激光选区熔化技术成形18Ni300马氏体时效钢试样,分别对成形试样进行时效处理和固溶+时效处理。通过金相显微镜、扫描电镜、显微硬度计和电化学工作站,分别测试分析了不同热处理SLM 18Ni300马氏体时效钢的微观组织、显微硬度和耐蚀性。结果热处理后,试样微观组织发生显著变化,时效试样组织细化,得到板条马氏体组织;固溶+时效试样激光熔池消失,组织为均匀致密的板条马氏体,且均有细小析出物弥散分布于晶界和板条间。时效处理和固溶+时效处理显著提高了SLM18Ni300马氏体时效钢硬度,SLM试样硬度为376.6HV1,时效试样和固溶+时效试样硬度分别为651.5HV1和641.8HV1。0.5 mol/L H2SO4溶液中,SLM试样的Jcorr最小,为1.375×10?3 A/cm2,耐腐蚀性最好,各试样耐蚀性优劣有SLM试样固溶+时效试样时效试样。3.5%NaCl溶液中,SLM试样的极化曲线有明显的钝化平台,且Jcorr最小,为3.630×10?6A/cm2,耐腐蚀性最好,各试样耐蚀性优劣有SLM试样时效试样固溶+时效试样。结论时效处理和固溶+时效处理后,SLM 18Ni300马氏体时效钢得到板条马氏体组织,硬度显著提高,但在H2SO4溶液和Na Cl溶液中的耐腐蚀性能有所下降。     

铸造SAF2906不锈钢在人工海水中的电化学阻抗谱

利用电化学工作站研究了铸态、固溶态、深冷态和时效态2906铸造超级双相不锈钢在人工海水中的电化学阻抗谱(EIS)特征.结果表明:不同热处理得到的2906铸造超级双相不锈钢在人工海水中呈现出相同的EIS特征,均由一个时间常数的容抗弧组成;相对铸态而言,固溶和深冷处理可降低双电层电容、提高阻抗模;而时效处理可使组织产生金属间相,导致双相不锈钢与人工海水之间的双电层电容提高,阻抗模降低7个数量级,且随时效时间的延长,两个参数的变化量越大,耐蚀性越差.     

中温时效对2205双相不锈钢析出相及晶间腐蚀性能的影响

双相不锈钢在加热过程中会出现各种析出相。本文主要研究了等温时效对DSS2205双相不锈钢微观组织和晶间腐蚀性能的影响。研究表明,对于固溶样品,没有析出相;在650℃时效0.5h后,有少量析出相,随着时效时间延长,析出相增加。双环电化学动电位测试表明,固溶态样品晶间腐蚀抗力最大,随着时效时间延长,材料晶间腐蚀程度逐渐加剧。     

固溶温度与2101节镍双相不锈钢耐蚀性的关系

采用金相显微镜、电化学动电位极化曲线和电化学阻抗谱等方法研究了固溶温度对2101节镍双相不锈钢耐蚀性能的影响。结果表明：随着固溶温度的提高,α相含量增加,γ相含量减少;Cl-作用下最先腐蚀的相为铁素体相,处于α相中未溶解的γ相的尺寸大小对2101节镍双相不锈钢耐蚀性会产生一定的影响,尤其1100 ℃温度下,α相中未溶细小的条状γ相使得耐蚀性严重降低。Cl-作用下最先腐蚀相为α相。固溶温度对α相中未溶解的γ相的大小及α、γ相界面均对其耐蚀性影响较大。     

双相不锈钢在H2SO4＋NaCI介质中的腐蚀磨损

测定了α γ双相不锈钢在H2SO4及H2SO4＋NaCI介质中的腐蚀率、磨损率、腐蚀磨损率和钝化膜破坏后的修复时间，研究了磨损表面的硬度变化以及摩擦系数的变化规律，观察了磨痕及磨屑形貌等，实验表明氯离子对双相不锈钢腐蚀磨损的影响与磨损表面的脆性剥落有关。     

17-4PH不锈钢480 ℃时效组织的动态演变规律

将17-4PH不锈钢锻棒固溶处理后油冷,然后选择在最佳的时效温度480 ℃时效保温0～5 h后空冷。通过光学显微镜(OM)、超景深显微镜、XRD、显微硬度仪等测试方法观察固溶、时效过程的组织演变和分析其沉淀硬化机理;采用电阻仪间接测试ε-Cu相动态时效析出过程对电阻的影响;并利用摩擦磨损试验机测试其耐磨性能。研究发现:17-4PH不锈钢固溶和时效过程没有残留奥氏体和逆转变奥氏体出现,热处理后出现板条状和块状两种马氏体形态,板条状马氏体硬度高于块状马氏体,随着时效时间的延长,两种马氏体硬度同步上升,时效析出明显提高了固溶态组织的硬度;时效2.0～2.5 h附近强化效果和耐磨性能最弱,可能与ε-Cu 相长大及与位错交互作用有关;硬度随时效时间的变化趋势与电阻正好相反。     

固溶处理对316L不锈钢晶间腐蚀性能的影响

采用浸泡方法研究了1100℃固溶0.25~2 h对316L不锈钢晶间腐蚀性能的影响,用光学显微镜观察了不同热处理状态316L不锈钢的显微组织与腐蚀形貌的演变,用显微硬度仪测定了不同热处理状态316L不锈钢的硬度。结果表明,在1100℃固溶时间越长,固溶态试样的显微硬度越高,晶粒尺寸越大。随着固溶时间的延长,固溶态试样的腐蚀失重略有降低,敏化态试样的腐蚀失重先迅速降低,然后不再降低。敏化态试样的腐蚀失重高于固溶态试样1倍以上。所有试样的腐蚀失重都随着腐蚀时间的延长逐渐增加。根据实验结果得出,在1100℃固溶0.5~1 h的试样具有较好的综合性能。     

固溶处理对双相不锈钢组织与性能的影响

研究了固溶处理工艺对双相不锈钢组织及力学性能的影响。对经不同温度固溶处理后的试样进行了性能检测,并借助OM、SEM及电化学等分析手段对2205的显微组组织、析出物及耐腐蚀性能等进行了观察和分析,结果表明:低温固溶时,双相不锈钢中易产生大量的脆性析出相(σ相)是导致其塑性恶化及耐蚀性降低的原因;提高固溶温度可减少σ相的析出,有利于双相不锈钢的塑性和耐蚀性的改善;此外,双相不锈钢中铁素体含量随固溶温度升高而增大,但其所占比例受冷速影响较小。     

Effects of Solution and Aging Treatments on Corrosion Resistance of As-cast 60NiTi Alloy

60NiTi alloy has become a competitive candidate for bearing applications due to its shape memory effect, superelasticity, high strength, hardness, excellent abrasion resistance and corrosion resistance, etc. However, the relationship between its corrosion resistance and heat treatment is not clearly understood. Therefore, we used OM, XRD, SEM and EDS to study the evolution of microstructure in as-cast, solution-treated and aged 60NiTi alloy. Besides, the potentiodynamic polarization and salt spray test were used to compare corrosion resistance of 60NiTi alloy and 316 stainless steel and to study the effect of microstructures on corrosion resistance of 60NiTi alloy. The results show that the corrosion resistance of as-cast 60NiTi alloy is comparable to that of 316 stainless steel, but the corrosion resistance of solution-treated and aged 60NiTi alloys is much superior. The significantly reduced Ni₃Ti phase after the solution and aging treatments is responsible for the remarkable improvement in the corrosion resistance of as-cast 60NiTi alloy.     

固溶处理温度对双相不锈钢在硫酸介质中腐蚀磨损行为的影响

采用销环式腐蚀磨损试验机研究了固溶处理的双相不锈钢在１０％Ｈ２ＳＯ４中的腐蚀磨损行为．腐蚀磨损率－载荷关系曲线表明：较高温度固溶的双相不锈钢在低载荷下的耐腐蚀磨损性比低温固溶的优，而在高载荷下却恰恰相反；阴极保护下（－６００ｍＶ，ＳＣＥ）具有同样的关系．扫描电镜观察证实，高温固溶处理产生大量铁素体而导致高载下出现脆性剥落是其耐腐蚀磨损性变坏的原因．     

Corrosion and wear behaviors of Al-bronzes in 5.0% H2SO4 solution

Steady-state corrosion and wear behaviors of two Al-bronzes, Cu-14Al-X and QAl9-4, in 5.0% H2SO4 solution were investigated. It is found that wear loss of bronzes in 5.0% H2SO4 solution is lower than that in water or in air, namely, it exhibits negative synergy between corrosion and wear. Further analysis shows that corrosive solution plays an important role in cooling of specimen during the sliding wear to prevent the reduction of the surface hardness of specimen, induced by frictional heat. On the other hand, the bronzes suffer a de-alloying corrosion, and a noble copper subsurface and patina form on the specimen surface in corrosive solution, which has a passive function for further corrosion. The noble copper subsurface experiences strain hardening during the corrosion and wear, resulting in the increase of the surface hardness thus the increase in wear resistance.     

Ti2Ni3Si/NiTi金属间化合物合金在H2SO4溶液中的腐蚀行为

利用激光熔炼材料制备技术,制得了由三元金属硅化物Ti2Ni3Si初生枝晶和枝晶间Ti2Ni3Si/Ti共晶组成的金属间化合物耐磨耐蚀合金;采用极化曲线、塔菲尔图(Tafel Plot)和交流阻抗(EIS)等技术,研究了合金在1 mol/L H2SO4溶液中的电化学腐蚀行为以及Ti含量对合金组织与耐蚀性的影响.结果表明:由于表面形成的稳定钝化膜及Ti2Ni3Si和NiTi的高化学稳定性,使合金在1 mol/L H2SO4溶液中具有优异的耐蚀性,且随着Ti含量的升高,合金的耐蚀性略有提高.     

PROPERTIES OF ELECTRODEPOSITED AMORPHOUS Ni-W-P-SiC COMPOSITE COATINGS

ＰＲＯＰＥＲＴＩＥＳＯＦＥＬＥＣＴＲＯＤＥＰＯＳＩＴＥＤＡＭＯＲＰＨＯＵＳＮｉ－Ｗ－Ｐ－ＳｉＣＣＯＭＰＯＳＩＴＥＣＯＡＴＩＮＧＳＧＵＯＺｈｏｎｇｃｈｅｎｇ;ＬＩＵＨｏｎｇｋａｎｇ;ＷＡＮＧＺｈｉｙｉｎ;ＷＡＮＧＭｉｎ（ＤｅｐａｒｔｍｅｎｔｏｆＭｅｔａ...     

Corrosion wear behavior of Al-bronzes in 3.5% NaCl solution

The corrosion wear behaviors of two aluminum bronzes, Cu-14Al-X and QAl9-4, in 3.5% NaCl solution were investigated on a pin-on-block reciprocating tester. It was found that the wear loss of the bronzes in 3.5% NaCl solution was lower than that in water and in air, i.e., it exhibited “negative” synergy between corrosion and wear. To understand the corrosion wear mechanism of the bronzes, the corrosion rate and polarization curves of Cu-14Al-X and QAl9-4 in 3.5% NaCl solution were determined. The worn surfaces of the specimens were examined, and the wear tracks were measured using scanning electron microscopy. The corrosion patinas formed on the specimen surfaces were studied with x-ray photoelectron spectroscopy and electron probe microanalysis. The corrosive solution was shown to play an important role in cooling of the specimen surfaces during the wear, thus preventing the specimen’s surface hardness from being reducing, induced by frictional heat during the sliding wear. On the other hand, the bronzes suffered from dealloying corrosion; a noble copper subsurface and patina formed on the specimen surface in the corrosive solution, which had a passive function for further corrosion. The noble copper subsurface experienced strain hardening during the corrosion wear, resulting in an increase of the surface hardness and thus an increase in wear resistance.     

Cl^—致脆对不锈钢磨蚀的影响及其判据研究

测定了ＡＩＳＩ３０４不锈钢在不同Ｃｌ＾－浓度的１ｍｏｌ／ＬＨ２ＳＯ４溶液中的静态腐蚀率及腐蚀损率。同时利用单摆冲击划痕实验机测定了不同条件下材料表面划痕的长度随冲击能耗的变化及其比能耗值,证明了随Ｃｌ＾－浓度的增加,材料表面的比能耗下降,即腐蚀及腐蚀磨损作用加剧原因系材料的表面变脆。     

等离子喷涂工艺对锅炉管束用Fe 基非晶涂层组织结构和耐蚀性能的影响

目的研究等离子喷涂功率和喷涂时间对锅炉管束用Fe基非晶涂层的相组成、微观组织结构及涂层耐蚀性能的影响。方法通过X射线衍射、扫描电子显微镜和三电极电化学研究进行分析。结果涂层主要由非晶相组成,表面较为平整致密;随着喷涂功率和喷涂时间的增加,涂层非晶相含量降低,孔隙率降低,致密性升高。非晶涂层在0.5mol/L H2SO4溶液和在3.5%(质量分数)NaCl溶液中均表现出良好的钝化作用,在0.5mol/L H2SO4溶液中钝化区较宽,在3.5%NaCl溶液中自腐蚀电流密度较低。随喷涂功率和时间的增加,阳极极化曲线钝化区加宽,电流密度降低。结论喷涂功率升高会导致涂层孔隙率下降,喷涂时间增加则致使涂层厚度增加,腐蚀介质渗透到基体的表面路径和阻力增加,从而可以进一步改善Fe基非晶涂层的耐蚀性能。     

The Effect of δ Phase on the Mechanical Properties of an Inconel 718 Superalloy

The relationship between the δ phase content and the mechanical properties of Inconel 718 superalloy is still uncertain in the scientific literature. This study investigated the effects of the amount of δ phase and of the grain size on the mechanical properties of an aged γ-matrix with γ′ and γ″ precipitates. The material in as-received condition in the form of a forged bar was solution-treated in different conditions and aged according to UNS7718 standard. The microstructures were characterized using optical, scanning, and transmission electron microscopy. Hardness and tensile tests were also conducted. After solution treatment, γ′ and γ″ phases are dissolved and δ phase volume fraction is reduced to a minimum amount only observed by TEM, resulting in an increase of the grain size and a decrease of hardness and strength. After aging, the precipitation of γ′ and γ″ occurs and the amount of δ phase increases. The volume fraction of δ phase varying from 0.30 to 1.38% and the grain size varying from ASTM 7 to 5 do not have a significant effect on the tensile properties and hardness.