热处理工艺对Inconel718合金组织、力学性能及耐蚀性能的影响

对高含H2S/CO2酸性油气田封隔器材料-Inconel718镍基合金进行固溶处理和时效处理,研究不同热处理工艺条件下合金的组织、力学性能、耐蚀性能之间的关系。结果表明:随着固溶温度的升高,δ相不断溶入基体。材料经时效处理后析出第二相γ″相,硬度和强度明显高于固溶处理的样品,1000℃固溶+720℃×8h→50℃/h620℃×8h时效处理的样品硬度和强度达到最大值。高温高压H2S/CO2介质中挂片实验的结果表明,不同热处理的Inconel718合金均具有良好的耐腐蚀性能,经固溶处理的材料耐腐蚀性略优于经固溶+时效处理的材料。高温高压H2S/CO2应力腐蚀实验的结果表明,Inconel718没有发生应力腐蚀开裂迹象。综合考虑耐蚀性能和力学性能,确定Inconel718合金的最佳热处理工艺为:1000℃固溶1h+720℃×8h→50℃/h620℃×8h时效。     

固溶处理和时效处理对HDR双相不锈钢耐蚀性的影响

为提高船舶用双相不锈钢在海水介质环境下的耐蚀性能，针对HDR双相不锈钢，采用固溶处理和时效处理工艺，通过3D显微镜、维氏硬度计、扫描电子显微镜、能谱仪等分析显微组织、成分、硬度和耐蚀性，研究其在3.5%NaCl溶液中的耐点腐蚀性能，从而确定合适的热处理工艺。结果表明：固溶温度为1 050℃～1 150℃时，时效处理促进脆性相σ析出，材料硬度提升；固溶温度为1 100℃时，HDR双相不锈钢耐点腐蚀性能最好；在1 050℃和1 150℃固溶温度条件下，时效处理明显削弱了不锈钢的耐蚀性。     

固溶时效处理对4043铝合金沉积层组织与性能的影响

目的 研究CMT增材制造的4043铝合金在固溶时效处理后的组织与性能变化规律。方法 利用基于冷金属过渡技术的金属丝材增材制造方法制造出4043铝合金试件,采用金相组织观察、硬度测试、室温拉伸性能测试、能谱分析等手段,观察并测试固溶时效处理后4043铝合金沉积层的组织与性能。结果 增材制造的沉积层与母材间的成分分布不均匀,Al多以树枝状晶形式存在,共晶Si以片状形式存在,固溶时效处理能够使沉积层内共晶Si聚集,元素扩散均匀。在540℃下固溶处理2 h、180℃下时效处理8 h后,性能提升最为明显。结论 使用增材制造方式制造零件后,可采用固溶时效处理的方式改善组织、提高性能,从而扩大使用范围。     

固溶时效处理对TM60合金组织和力学性能的影响

通过对8型钛合金TM60进行不同制度的固溶时效处理,研究了各制度下其显微组织、相结构和力学性能的变化。研究结果表明：α相的含量和体积分数对合金性能有较大影响,固溶处理温度选择在700℃,时效处理温度应选择在400℃~450℃,β型钛合金TM60具有最佳的强塑性。     

热处理对2519铝合金接头组织及性能的影响

研究了焊后时效及固溶＋时效热处理对2519铝合金焊接接头组织和力学性能的影响．结果表明,时效处理后,处于欠时效态的焊缝析出强化相增加,硬度升高,而过时效态的热影响区软化区组织和硬度没有明显变化,焊接接头的强度略微提高,塑性下降．固溶＋时效处理后,焊缝中网状共晶减少,焊缝和热影响区软化区内的析出相形态变为细小的针状,且数量增加,焊缝金属硬度明显提高,热影响区的软化现象消失,焊接接头的强度和塑性显著增加．     

固溶时效处理对Cu-Al合金机械性能的影响研究

以Cu-Al-Ni-Fe-Mn为研究对象,在固定固溶处理温度为900℃、固溶时间为1 h的条件下,通过改变时效处理温度,研究了不同时效处理温度对Cu-Al合金性能的影响。采用洛氏硬度计、SEM、电子万能试验机等对铜铝合金的洛氏硬度、微观形貌和力学性能等进行了分析。结果表明,随着时效处理温度的升高,Cu-Al合金的硬度、抗拉强度和断裂延伸率均先升高后降低,当时效处理温度为550℃时,Cu-Al合金的硬度达到了最大值45.2 HRC,抗拉强度和断裂延伸率分别达到最大值895.8 MPa和2.38%,时效处理效果最佳。形貌分析可知,随着时效处理温度升高到550℃,Cu-Al合金的硬质相和第二相粒子增多,沉淀强化的效果增强,且断口形貌的韧窝加深,位错滑移的难度增加,从而使Cu-Al合金的力学性能得到了显著改善。综合可知,Cu-Al合金的最佳时效处理温度为550℃。     

6016铝合金热处理工艺研究

通过硬度测试、力学性能测试和烘烤硬化性能测试,研究了6016铝合金冷轧板材的热处理工艺,结果表明:合金的硬度随着固溶温度升高和固溶时间延长而增加;合金进行预时效处理时,随着预时效时间的增加硬度出现先降低后升高的现象,且预时效温度越高,硬度下降值越大;在本试验条件下,满足覆盖件性能要求的6016合金的热处理工艺为:540℃×20 min固溶水淬+120℃×10 min预时效处理。     

不同时效处理的Ti-29Nb-13Ta-4．6Zr合金的组织结构和医用性能

Tj—Nb-Ta-Zr系合金有很好的生物材料应用前景,国内对其研究较少。真空熔炼制备了Ti-29Nb．13Ta-4．6Zr铸锭,对其固溶处理后在不同温度、时间下时效处理,研究了合金时效处理后的组织结构和医用性能。结果表明：830℃固溶1．5h后的Ti-29Nb-13Ta-4．6Zr合金是单一的过冷亚稳B相,再经时效加热...     

热处理对挤压变形AM20镁合金疲劳性能的影响

本文研究了固溶处理和固溶＋时效处理对挤压变形AM20镁合金低周疲劳性能的影响。结果表明,不同制度的热处理对挤压变形AM20镁合金循环变形抗力的影响与外加总应变幅的高低有关;不同处理状态的挤压变形AM20镁合金的塑性应变幅、弹性应变幅与疲劳断裂时的载荷反向周次之间的关系可分别用Coffin--Manson和Basquin公式来描述。此外,不同处理状态的挤压变形AM20镁合金的循环应力幅与塑性应变幅之间呈线性关系。     

0Cr17Ni7Al高强度不锈弹簧钢丝热处理工艺制度的研究

本文探讨了0Cr_(17)Ni_7Al高强度不锈弹簧钢丝在不同固溶处理、变形度及时效处理条件下性能的变化情况;提出了合理的工艺制度,并对C、Al等成份变化、形变时效等作了评述与讨论。认为:CH工艺制度可以获得所需的高强度,1050℃固溶处理,变形度大于60％。450℃时效处理可以获得最佳性能。     

Microstructural impact on intergranular corrosion and the mechanical properties of industrial drawn 6056 aluminum wires

The influence of individual manufacturing steps during industrial wire drawing processes on the mechanical and corrosion properties of the 6056 aluminum alloy was investigated. These steps demonstrated an essential influence on the microstructure, and thus, the susceptibility to intergranular corrosion (IGC). No clear correlation between IGC susceptibility and hardness was observed. Although the highest resistance against intergranular attack was determined for those alloys in the solution annealed condition, pitting corrosion was identified to occur. Subsequent artificial aging of the solution annealed and quenched wires reintroduced IGC susceptibility; this phenomenon was attributed to the occurrence of galvanic coupling between the noble Cu-phases, located on the grain boundary, and the anodic grain boundary area.     

时效处理对4A双相不锈钢σ相析出及性能的影响

对固溶处理后的4A双相不锈钢(DSS4A)进行不同温度(750~900℃)的等温时效处理,利用OM观测各个时效温度下σ相的析出行为,重点观测了σ相在850℃时效不同时间(1h、2h和4h)的析出过程,并通过SEM、EDS和TEM等检测手段对850℃、4h时效处理后的σ相析出形貌进行分析,揭示了σ相的析出特征及形成机理。最后对时效条件下4A双相不锈钢的力学性能和耐蚀性能也进行了相应研究。结果表明:σ相富Cr、Mo而贫Ni,属于四方结构,由高温铁素体分解而成;σ相析出量随时效温度的升高先增加后降低并在850℃时达到峰值,同一温度下时效时间越长,σ相析出越多;σ相使材料硬度提高,但材料抗拉强度、冲击韧性和耐腐蚀性整体呈下降趋势,其中冲击韧性对σ相析出尤为敏感。     

锂电池PACK包Al-Zn-Mg-Cu铝合金CMT 焊接组织与性能研究

以锂电池包箱体常用的7003铝合金为研究对象,采用冷金属过渡焊接工艺(CMT)对7003铝合金进行焊接后,经过固溶(485 ℃,3 h)、人工时效(160 ℃,2 h)和自然时效(72 h)热处理后,进行组织和性能研究。通过慢应变速率拉伸试验、常温拉伸试验、显微维氏硬度测试、扫描电子显微镜分析等方法,对该铝合金接头的母材和焊缝的抗腐蚀性能、力学性能以及微观组织形貌进行研究。结果表明:当慢应变速率为1×10-6 s-1时,基材和焊接试样的应力腐蚀敏感性指数(ISSRT)分别为2.73%和9.74%;对焊接试样的接头进行晶间腐蚀和剥落腐蚀测试并评级,晶间腐蚀为4级,剥落腐蚀为PA级;焊接接头的电导率、抗拉强度、延伸率分别为22.0%(IACS)、330.7 MPa、10.0%。     

固溶处理对 0Cr17Ni4Cu4Nb钢耐腐蚀性能及组织的影响

运用极化曲线、循环极化曲线等电化学方法研究了0Cr17Ni4Cu4Nb钢经不同工艺固溶处理后的耐海水腐蚀性能,并对显微组织进行了观察和分析。试验结果表明:在1040℃下该不锈钢经60min固溶处理可获最佳的耐海水腐蚀性能和较高的硬度值。其显微组织主要为淬火马氏体+少量的残余奥氏体+δ-铁素体,且晶粒大小均匀。     

Microstructures and properties evolution of Al-Zn-Mg-Cu alloy under electrical pulse assisted creep aging

Creep aging (CA) is a promising forming technology for integral panels with complex structures. However, how to balance excellent corrosion resistance and strength is still a challenge for CA parts. By synchronously applying electrical pulse (300 Hz, 15 A/mm²) in the middle of steady-state CA of Al-Zn-Mg-Cu alloy, the electrically assisted CA (ECA) is proposed to induce retrogression rapidly for realizing a three-step aging (retrogression and re-aging, RRA) in CA to tailor the needed properties balance. It is compared with conventional CA with one-step aging (peak aging, T6 or over aging, T7), two-step aging (over aging, T73) and RRA in hardness, intergranular corrosion and microstructures. For the ECA of pre-aging and re-aging for 20 h plus electropulsing for 10 min, the hardness is 10.5%, 20.5% and 18.9% higher than those of CA with T6, T7 and T73 processes, respectively, while the corrosion resistance is higher than T6 process and lower than T7 and T73 processes. Although the hardness and corrosion resistance are comparable to those of the CA with the RRA process, ECA takes one hour less due to the accelerated effect of the electropulsing and is not limited by the thick plates. The improved comprehensive performance of the ECA sample is due to both fine intragranular precipitates η′ and large discontinuous grain boundary precipitates η.The full text can be downloaded at https://link.springer.com/article/10.1007/s40436-022-00404-2     

Corrosion resistance of the layers formed on the surface of plasma-nitrided AISI 304L steel

Austenitic stainless steels have good corrosion resistance, but their low hardness and low wear resistance limit their use whenever surface hardness is required. Nitriding treatments have been successfully applied to stainless steels to improve their mechanical and tribological properties; however, at temperatures above 723 K, gas or salt bath nitriding processes decrease the corrosion resistance due to the formation of CrN and other phases within the modified layer. Chromium compounds draw chromium and nitrogen from the adjacent regions, degrading the corrosion resistance. The plasma nitriding technique permits the use of treatment temperatures as low as 623 K without promoting degradation in the corrosion resistance of stainless steel. In this work, the pulsed glow discharge (PGD) technique was used for nitriding steel (AISI304L) in order to investigate the effect of the temperature of this treatment in the morphology and, as a consequence, in the anodic behavior of the formed layers, in solution with and without chloride ions. Four different temperatures were employed (623, 673, 723, and 773 K). The samples were characterized by optical microscopy (OM), scanning electron microscopy (SEM) with energy-dispersive spectroscopy (EDS), X-ray diffraction (XRD), microhardness measurements, and electrochemical tests with potentiodynamic anodic polarization curves. The nitriding temperature alters the anodic behavior due to a displacement of the polarization curve towards higher currents, in a solution free of chloride ions. In a chloride solution, the nitriding temperature increases the pitting potential up to the oxygen evolution region.     

Effect of molybdenum on SCC of 17-4PH stainless steel under different aging conditions in chloride solutions

Type 17-4 PH martensitic precipitation-hardenable stainless steel, having a combination of high mechanical properties and good corrosion resistance is widely used in aerospace, chemical, and petrochemical and food industries This alloy has a high resistance to stress corrosion cracking but age hardening treatment, increases its sensitivity to stress corrosion cracking. There are several works investigating the influence of different aging treatments on the microstructure, mechanical properties and corrosion resistance of 17-4 PH steels, however there are little works studying the simultaneous effects of aging treatments and molybdenum content on corrosion properties of these steels. In this research, the effect of molybdenum on stress corrosion cracking resistance of 17-4 PH alloy using U-bend samples in chloride solutions, as well as its effect on passivity, has been investigated. Quantometer, Scanning Electron Microscope(SEM) and potentiostat were used to determine the chemical composition, microstructure and anodic polarization behavior of the alloys. It is found that molybdenum has a useful effect on stress corrosion cracking resistance under the peak aged conditions, and this is because of development of delta-ferrite phase by increasing the molybdenum content and subsequently decreasing the strength of the alloy.     

国产涂料在核电汽轮机蒸汽侧应用的可行性研究

为了降低核电汽轮机对进口涂料的依赖,通过污染物分析、盐雾试验、紫外老化试验、焊缝强度和硬度测试等研究了国产涂料在核电汽轮机蒸汽侧应用的可行性。结果表明:国产涂料中汞(Hg)、六价铬Cr(VI)、氟(F)、氯(Cl)、硫(S)、砷(As)、亚硝酸根(NO2-)和铅(Pb)的含量均满足限值要求,不会诱发核电汽轮机蒸汽侧部件的应力腐蚀;国产涂料的硬度、冲击强度、附着力、柔韧性和耐热性与进口涂料相当,耐盐雾性和耐紫外老化性能略优于进口涂料;国产涂料对焊接试板硬度、冲击和弯曲性能均无不良影响,在核电汽轮机蒸汽侧应用是可行的。     

脉冲电沉积Ni-W-P合金工艺的研究

为了研究Ni-W-P合金脉冲电沉积中脉冲参数对镀速和镀层中钨、磷含量的影响以及对镀层耐蚀性和硬度的影响,采用称重法、硫酸浸泡法、日本岛津EPMA-1600型电子探针以及HX-1型显微硬度计对Ni-W-P合金工艺进行了研究.结果表明,镀层的沉积速率、镀层成分及镀层的性能都随脉冲频率和占空比的变化而变化;Ni-W-P镀层的脉冲电沉积速率比直流电沉积大,脉冲镀层的耐蚀性和硬度都优于直流镀层,其耐蚀性还优于1Cr18Ni9Ti不锈钢.本工艺操作方便,镀层性能稳定.