共查询到15条相似文献,搜索用时 89 毫秒
1.
2.
3.
机械压磨诱导0Cr21Mn17Mo2NbN0.83高氮奥氏体不锈钢表面纳米化 总被引:1,自引:1,他引:0
塑性变形技术可实现金属纳米材料的制备,并且可改进材料的表面性能。本研究设计一种镶嵌滚珠的摩擦头并安装在铣床上,对经1150℃等温10h、水冷处理后的高氮奥氏体不锈钢0Cr21Mn17Mo2NbN0.83(钢板、厚度8mm)进行表面机械压磨处理,利用光学显微镜、扫描电镜(SEM)、透射电镜(TEM)、XRD、显微硬度仪等研究分析了经机械压磨处理后实验钢表面层组织及硬度的变化,同时考察了奥氏体表面层的结构稳定性。结果表明:经240min、360min、480min机械压磨处理后,可获得具有纳米尺度的表面层,且表面层的组织稳定,仍为单相奥氏体。由表面至距表面700μm深度区域,晶粒尺寸呈梯度递增趋势;硬度由表面至基体逐渐减小,表面硬度较基体硬度提高1倍以上。 相似文献
4.
热力学计算在高氮奥氏体不锈钢研究中的应用 总被引:2,自引:0,他引:2
采用Thermo-Calc软件,计算了碳、铬、锰、镍元素和压力因素对22Cr高氮奥氏体不锈钢氮溶解度、凝固过程中相转变以及析出相的影响,并对设计的新型高氮奥氏体不锈钢组织及析出相进行了研究。结果表明:铬元素主要增加液态钢的氮溶解度,增加0.1%(质量分数)的碳即能显著增大奥氏体不锈钢在高温凝固时的最小氮溶解度。锰元素既增加液态钢中的饱和氮溶解度,又增加凝固初期的最小氮溶解度。适当的锰含量能扩大并稳定奥氏体相区,避免"铁素体阱"的出现。少量的镍含量既增加奥氏体不锈钢高温凝固时的最小氮溶解度,缩小高温δ铁素体存在的温度区间,也能使钢在室温下有完全的奥氏体组织。加压冶炼能有效促进氮溶解度。新型高氮奥氏体不锈钢的析出相主要为Cr23C6,Cr2N。采用热力学计算工具可以对高氮奥氏体不锈钢的冶炼、组织控制、热处理和热加工提供科学的指导。 相似文献
5.
6.
采用粉末冶金方法制备了多孔高氮奥氏体不锈钢并研究其力学性能和耐腐蚀性能。结果表明,高温气固渗氮能促进双相不锈钢向奥氏体不锈钢的转变,在其显微组织中出现了细条状和颗粒状CrN相析出物。随着造孔剂含量的提高孔隙率随之提高,而力学性能和耐腐蚀性能降低。与普通的多孔不锈钢相比,这种多孔高氮奥氏体不锈钢的力学性能更加优越,源于N的固溶强化和CrN等析出物的强化机制。随着孔隙率的提高多孔高氮奥氏体不锈钢的腐蚀倾向和腐蚀速率逐渐增大,造孔剂含量(质量分数)为10%的试样具有最佳的耐腐蚀性能。提高烧结温度有利于烧结块体的致密化,使腐蚀速率明显下降。 相似文献
7.
主要探讨不同含氮量的无镍奥氏体不锈钢材料对血管内皮细胞及血小板粘附的影响。通过溶血率和血小板粘附试验考察不同含氮量的无镍奥氏体不锈钢材料的血液相容性;通过MTT试验和细胞粘附试验考察不同含氮量的无镍奥氏体不锈钢材料的细胞相容性。结果表明不同含氮量的无镍奥氏体不锈钢材料的溶血率都低于国家标准的5%,对血小板粘附的影响不显著;粘附在高氮无镍奥氏体不锈钢材料表面的血管内皮细胞数量均多于钛合金材料,且细胞生长状态良好;细胞毒性试验表明,不同含氮量的高氮无镍奥氏体不锈钢材料和对照组钛合金材料对血管内皮细胞没有产生明显的毒副作用。 相似文献
8.
用热压缩试验方法研究了22Mn-13Cr-3Ni-1Mo-1Cu-0.22N奥氏体不锈钢的动态再结晶。获得在热压缩变形条件下该钢的热变形方程式,并求出峰值应力σ_p和峰值应变ε_p与Zoner-Hollomon参数Z间的关系式以及动态再结晶激活能。 相似文献
9.
10.
目前产于高氮不锈钢的研究多集中于理论基础、制造工艺和力学性能等方面,有关耐蚀性方面的研究有限。通过循环极化、Mott-Schottky曲线以及电化学阻抗(EIS)等方法,研究了Cr23Mo1N奥氏体不锈钢(高氮钢,HNSS)和316L不锈钢在Cl-溶液中的耐点蚀性能。结果表明:与316L不锈钢相比,高氮钢具有更正的自腐蚀电位,更小的维钝电流密度。阻抗谱表明高氮钢的钝化膜比316L更加稳定,且电荷转移电阻更大。Mott-Schottky曲线表明高氮钢的点缺陷施主浓度比316L不锈钢低一个数量级,钝化膜的绝缘性更好。循环极化曲线表明高氮钢的点蚀敏感性更小,钝化膜的自修复能力更强,耐蚀性能更加优越。 相似文献
11.
12.
Yibin Ren ) Peng Wan ) Feng Liu Bingchun Zhang ) Ke Yang ) ) Institute of Metal Research Chinese Academy of Sciences Shenyang China ) Graduate School of Chinese Academy of Sciences Beijing China 《材料科学技术学报》2011,(4):325-331
Most commercialized coronary stents are made of 316L stainless steels due to its good combination of properties,and currently some new stents are made of cobalt-based alloy owing to its higher mechanical properties. However,the presence of high quantity of nickel and/or cobalt elements in these materials,which are known to trigger the toxic and allergic responses,has caused many concerns.Nickel-free austenitic stainless steels have been developed in order to solve these problems.In this paper,based on the development of a new Fe-Cr-Mn-Mo-N type high nitrogen nickel-free austenitic stainless steel,properties such as mechanical property,corrosion resistance in Hank s solution,and in vitro blood compatibility including the kinetic clotting time and the platelets adhesion,were investigated in comparison to the above two conventional materials,a 316L stainless steel and a Co-28Cr-6Mo alloy.The results showed that the new high nitrogen steel possessed better combination of mechanical properties,corrosion resistance and blood compatibility than those of 316L steel and the Co-28Cr-6Mo alloy,and can be a promising alternative material for manufacture of coronary stents. 相似文献
13.
Generally the methods of solution treatment of austenitic stainless steel are bifurcated on-line solution and off-line solution . For a founded enterprise, it is necessary to find out how to get across alterations and search a measure of on -line solution disposal with less investment and higher efficiency. By studying and analysingin laboratory, several key points and the methods settle them are presented, which offers a new route to realize austenitic stainless steel on-line solution. By reducing the cost greatly, it makes the enterprise larger benefits. 相似文献
14.
Stable austenitic structure in medical stainless steels is basically required for surgical implantation. A weak magnetism was found in a high nitrogen nickel-free austenitic stainless steel for cardiovascular stent application. This magnetic behavior in high nitrogen stainless steel was investigated by optical microscopy, X-ray diffraction (XRD), electron probe microanalysis (EPMA) and superconducting quantum interference device (SQUID). The results showed that the magnetism came from the composition segregation of ferrite formation elements such as Cr and Mo in the steel and some δ-ferrites were locally formed during the pressurized electroslag remelting process. The magnetism of high nitrogen stainless steel could be eliminated by a proper high temperature gas nitriding (HTGN). 相似文献