Fu-Yuan Dong
,
Peng Zhang
,
Jian-Chao Pang
,
Qi-Qiang Duan
,
Yi-Bin Ren
,
Ke Yang
,
Zhe-Feng Zhang
金属学报(英文版)
doi:10.1007/s40195-016-0370-9
Three high-nitrogen stainless steels with different N contents were successfully processed by equal-channel angular pressing for one pass, and their microstructures and mechanical properties were investigated. It was found that the microstructure of the billet was heterogeneous across the billet thickness, resulting in the difference in the mechanical properties due to the different deformation conditions. A relatively low strength, high uniform elongation, and high work-hardening rate for the samples at the bottom of the billet was achieved in comparison with those processed at the top. Meanwhile, it was observed that the density of deformation twins increased with the content of N; accordingly, the strength and elongation of the alloys increase with the content of N, resulting in a good strength-ductility combination.
关键词:
High-nitrogen
,
stainless
,
(HNS)
,
steels
,
Equal-channel
,
angular
,
pressing
,
(ECAP)
,
N
,
content
,
Twinning
,
Strength
,
Ductility
Wei LIU
材料科学技术（英文）
Transformation induced plasticity (TRIP) and twinning induced plasticity (TWIP) effects had been widely studied in single austenite steel. But in duplex γ & α(δ) phase, such as welding materials of stainless steel, they had been less studied. Tensile shear loading experiment of resistance spot welding specimens prepared with 2 mm 301L sheets, was carried out at 15℃ and -50℃. Optical microscopy and scanning electron microscopy (SEM) as well as X-ray diffraction (XRD) were used to investigate the microstructure of weld nugget, and specimens fracture surface. The results showed that the initial weld nugget was composed of 8.4% α(δ) ferrite and 91.6% austenite. Tensile shear load bearing capacity of spot welding specimen at -50℃ was 24.8 kN, 17.7% higher than that at 15℃. About 78.5 vol. pct. martensite transformation was induced by plastic deformation at -50℃, while about 67.9 vol. pct transformation induced at 15℃. The plasticity of spot welding joint decreased with the decline of experimental temperature.
关键词:
301L stainless steel
,
stainless
,
steel
,
Resistance
,
spot
,
wel
Li NAN
材料科学技术（英文）
A preliminary study was made on the antibacterial mechanism of copper-bearing antibacterial stainless steels against E.coli through experiments of microbiology such as EDTA (ethylenediaminetetraacetic acid) complexing, DNA smearing and AFM (atomic force microscope) observation. It was measured that the antibacterial stainless steels showed excellent antibacterial functions with antibacterial rate to E.coli over 99.99%. The antibacterial rate was weak if the bacteria solution was complexed by EDTA, indicating that the copper ions play a dominant role in the antibacterial effect of the antibacterial stainless steels. The electrophoresis experiment did not show the phenomenon of DNA smearing for E.coli after contacting antibacterial stainless steels, which meant that DNA of E.coli was not obviously damaged. It was observed by AFM that the morphology of E.coli changed a lot after contacting antibacterial stainless steels, such as cell walls being seriously changed and lots of contents in the cells being leaked.
关键词:
copper
,
stainless
,
steel
,
E.coli
,
antibacter
Y.T. Xi
,
D.X. Liu
,
D. Han
,
Z.F. Han
,
null
,
null
,
null
,
null
金属学报(英文版)
A series of experiments were carried out to study the influence of low temperature plasma nitriding on the mechanical properties of AISI 420 martensitic stainless steel. Plasma nitriding experiments were carried out for 15 hours at 350℃ by means of DC-pulsed plasma with 25%N2+75%H2 gas. The microstructure, phase composition and residual stresses profiles of the nitriding layers were determined by optical microscopy and X-ray diffraction. The microhardness profiles of the nitriding surfaces were also studied. The fatigue life, sliding wear and erosion wear loss of the untreated specimens and plasma nitriding specimens were determined on the basis of a rotating bending fatigue tester, a ball-disk wear tester and a solid particle erosion tester. The results show that the 350℃ nitriding surface is dominated by -Fe3N and , which is supersaturated nitrogen solid solution. They have high hardness and chemical stabilities. So the low temperature plasma nitriding not only increases the surface hardness values but also improves the wear and erosion resistance. In addition, The fatigue limit of AISI 420 steel can also be improved by plasma nitriding at 350℃， because plasma nitriding produces residual compressive stress inside the modified layer.
关键词:
Martensitic stainless steel
,
stainless
,
steel
,
Plasma
,
nitri
熊佳龙
,
张根元
,
耿都都
,
薛岩
腐蚀与防护
引入H2SO4+NaCl电解液采用EPR法测试304不锈钢的晶间腐蚀.通过田口方法对[H2 SO4]、[NaCl]、回扫电位U和扫描速度率v等试验参数进行了研究,获得H2SO4+NaCl电解液的优化测试参数为:1.0 mol·L-1H2SO4+0.5 mol·L1 NaCl,v=60 mV·min-1,U=300 mV.与现行电解液0.5 mol·L-1H2SO4+0.01 mol·L1 KSCN在v=100 mV·min-1,U=300 mV条件下的试验结果进行比较,结合金相研究,结果表明,基于H2SO4+ NaCl电解液的EPR法能评价304不锈钢的敏化度,且测试条件更接近304不锈钢的实际腐蚀条件.
关键词:
304不锈钢
,
晶间腐蚀
,
H2SO4+NaCl电解液
,
EPR法
张维科
,
黄茜
,
姚波
腐蚀与防护
采用动电位阳极极化法测定了不同工况下TP304不锈钢凝汽器管的点蚀电位,研究了TP304不锈钢发生点蚀的规律.结果表明,TP304不锈钢在凝汽器正常运行和结垢情况下均具有较强的耐点蚀能力,一般不会发生大面积的快速腐蚀穿孔;当循环水中加入不同含量盐酸后,TP304不锈钢在有氧条件下的耐点蚀能力产生较大差异.盐酸质量浓度0.03％时,耐点蚀能力较强;盐酸质量浓度为0.07％与0.2％时,不耐点蚀,容易发生快速点腐蚀穿孔;盐酸质量浓度0.5％时,主要发生快速均匀腐蚀减薄.根据分析结果,提出了防止TP304不锈钢凝汽器管腐蚀泄漏的建议.
关键词:
不锈钢
,
凝汽器
,
点蚀
,
点蚀电位
,
平衡电位
张微啸
,
李成涛
,
陈建军
,
赵彦芬
,
徐为民
,
沈剑
,
费克勋
腐蚀与防护
采用动电位极化曲线、电化学阻抗谱、扫描电镜和能谱分析方法研究了304L不锈钢在硼酸水溶液中的腐蚀行为.结果表明,304L不锈钢的自腐蚀电位和腐蚀电流密度随着硼酸水溶液温度的升高而增大;不同温度下的电化学阻抗谱呈单容抗弧,表现为一个时间常数,80 C硼酸水溶液中的阻抗模值较小;随时间的延长,304L不锈钢的均匀腐蚀速率逐渐降低,并且维持在较低的腐蚀速率.
关键词:
304L不锈钢
,
极化曲线
,
电化学阻抗谱
,
腐蚀速率
敖庆波
,
汤慧萍
,
王建忠
,
支浩
,
马军
,
鲍腾飞
材料导报
针对电子元器件对多孔复合隔声薄板的高效隔声应用要求,以316L不锈钢纤维为原料通过真空烧结法制备出不同孔隙结构的多孔材料,并与穿孔板制成复合结构,重点研究了多孔材料孔隙结构参数及复合形式对吸声性能的影响,以达到提高复合吸声材料吸声性能的目的.结果表明:将优化的穿孔板与多孔材料复合构成吸声结构,有效地提高了中低频率吸声性能(＜3000 Hz),吸声系数最大提高至0.8.
关键词:
不锈钢纤维复合材料
,
穿孔板
,
吸声性能
