不锈钢真空钎焊

简述了不锈钢真空钎焊技术的应用、原理、工艺及设备情况,并概述了不锈钢真空钎焊技术的发展趋势.     

某大型压水堆不锈钢螺柱焊的质量影响因素及质量控制措施

本文主要从焊接参数、设备性能、操作因素等方面叙述了某大型压水堆不锈钢螺柱焊的质量影响因素。结合生产实际,在大量的工艺试验及产品焊接的基础上,总结了不锈钢螺柱与双相不锈钢焊接的质量控制措施,提出了采用熔化值作为衡量焊缝质量的工艺控制指标。     

不锈钢导管焊接工艺研究

随着科技的不断进步,新的焊接材料、先进的焊接技术层出不穷,提高了焊接工艺的效率和质量。虽然不锈钢导管本身具有非常好的抗腐蚀性,但是由于在焊接时电流使用不合理、未焊透、未溶合等一些原因,使得不锈钢导管采用新的焊接技术时焊接时,在焊接处出现了腐蚀、气孔、开裂等现象。本文将对不锈钢导管的焊接工艺进行深入的探讨,探讨出不锈钢导管焊接时易出现的问题及原因,并提出一些合理的加强措施,保证不锈钢导管的焊接工艺更加的高效、高质。     

Alloy 20不锈钢薄板等离子弧焊接工艺研究

对Alloy 20不锈钢薄板进行了等离子弧焊接工艺试验研究。结果表明,采用等离子弧焊接方法、ERCr Ni Mo-3焊材及合理的焊接工艺参数,等离子弧焊接工艺可用于Alloy 20不锈钢薄板的焊接,焊接接头各项性能均能满足要求。     

不锈钢光亮钝化新工艺

最近上海冶金设计院依据不锈钢钝化的几种理论现点和钝化机理,研制出不锈钢光亮钝化新工艺,经该工艺处理的不锈钢,表面质量稳定,从根本上消除了氮氧化物及氟污染,其工艺过程如下:     

锥形粉末冶金过滤器的研制EI

较详细地论述了不锈钢粉末冶金过滤器的制造工艺及原始粉末形状、粒度、压制压力和烧结温度对过滤性能的影响。采用合理的工艺参数研制出性能达到国际水平的不锈钢粉末冶金过滤器并已用于生产。     

锥形粉末冶金过滤器的研制

较详细地论述了不锈钢粉末冶金过滤器的制造工艺及原始粉末形状、粒度、压制压力和烧结温度对过滤性能的影响。采用合理的工艺参数研制出性能达到国际水平的不锈钢粉末冶金过滤器并已用于生产。     

激光增材制造不锈钢的凝固组织及调控方法研究进展

激光增材制造技术成形的制件具有自由度大、精度高、质量和性能好等优势,随着该技术的日益发展,其在不锈钢材料领域取得了显著的进展。激光增材制造技术成形不锈钢通常呈现出与传统制备工艺显著不同的非平衡凝固组织,表现出复杂的结构特征,而这些特征决定了合金的性能和应用。介绍了激光熔化沉积和选区激光熔化两种激光增材制造技术,选择典型的316L不锈钢及17-4PH不锈钢,综述了激光增材制造不锈钢凝固组织特征的研究现状,重点关注典型多尺度、层次性的组织结构（包括晶粒、宏观缺陷、熔池组织、胞状亚结构、氧化物夹杂等）。系统分析了激光增材制造不锈钢的组织调控方法,包括调整工艺参数、改变工艺环境及热处理等方式,通过组织调控能够影响晶粒的生长及熔池反应,进一步改善其内部微观组织,如形成间隙固溶体或颗粒夹杂物、细化晶粒及消除孔隙等,同时能促进不同相的析出和转变。通过合理地调控凝固组织,能够显著改善不锈钢的组织及机械性能。最后,对激光增材制造不锈钢的未来发展进行了展望。     

锆/不锈钢复合板界面形态及性能分析

研究了不同工艺参数条件下双层锆/不锈钢复合板的界面形貌及力学性能之间的关系。通过金相及能谱分析对结合界面的波纹尺寸、脆性相成分进行测定,通过力学性能检测对结合质量进行评定。通过对爆炸复合不同工艺条件下锆/不锈钢复合板的界面结合情况进行对比,确定了最佳的复合工艺。最佳工艺条件下,界面波长为1 400 μm,波幅为230 μm,剪切强度达260 MPa。研究结果对双层锆/不锈钢复合板的国产工业化生产具有一定的参考意义。      

不锈钢着色工艺及彩色不锈钢的应用

概述了不锈钢着色的原理、着色工艺、着色膜硬化处理工艺、着色处理过程的管理。讨论了彩色不锈钢板的性能及彩色不锈钢的应用。     

不锈钢超精抛光蜡的研制

目前,国产不锈钢超精抛光蜡不能满足市场需求,对其配方研制报道较少。为此,对不锈钢粗抛光后,采用超精抛光蜡进行精抛光,对其组分进行了筛选：以仪型氧化铝粉为抛光磨料;以混合硬脂酸作抛光内脂;利用油酸的润滑作用降低不锈钢表面的抛光温度,利用三乙醇胺与有机酸的皂化反应生成物润滑和清洁不锈钢表面;利用松香和石油磺酸钡提高不锈钢表...     

不锈钢化学抛光工艺研究

研究了以硫酸为主的不锈钢化学抛光工艺。通过改变温度考察其对不锈钢抛光效果的影响，从而确定最佳温度范围；通过改变不锈钢化学抛光工艺中各组成的含量，考察其对抛光效果的影响，筛选出既有较好抛光效果、抛光成本也较低的最佳化学抛光工艺为：H2SO4 20％-30％，HNO3 3％-6％，添加剂3％-6％，水余量，温度60-70℃，时间3-5min。     

金相试样制备技巧及具体方法

合理的金相试样制备方法是获得清晰、高质量显微组织图像的保障,是材料金相研究的基础.对高纯钨、高氮不锈钢、汽车钢板、涂层材料的金相制备技巧及具体方法进行了分析,解决了制样中切割、镶嵌、磨抛和浸蚀等过程遇到的问题.结果表明:高纯钨硬度高,要保证磨抛时间;高氮不锈钢采用三氯化铁盐酸甘油混合液浸蚀,可获得浸蚀均匀的显微组织形貌...     

A novel method for the growth of ZSM-5 zeolite membrane on the surface of stainless steel

Thin ordered micropore ZSM-5 zeolite membrane has formed on the stainless steel surface. The influence of three different pre-treatment methods for the growth of ZSM-5 zeolite membrane on the stainless steel was studied, including mechanical polishing, soaking in a 20 wt.% sulfuric acid aqueous solution and anodic oxidation treatment. It was found that the anodic oxidation technique was more favorable for the growth of ZSM-5 zeolite membrane on the stainless steel surface compared with the other two methods. By this appropriate pre-treatment process, ordered ZSM-5 zeolite membrane was immobilized on the stainless steel surface and it showed good interaction with the stainless steel. Energy-dispersive X-ray (EDX) spectroscopy result indicates that the ZSM-5 zeolite membrane has a Si/Al ratio of 37. X-ray diffraction (XRD), N₂ adsorption and scanning electron microscopy (SEM) were used to study the crystal structure, specific surface area and morphologies of the ZSM-5 zeolite membrane.     

Electrochemical polishing of 316L stainless steel slotted tube coronary stents

Surface smoothness is one of the properties determining the performance of stents. Therefore, surface polishing shows its importance in the exploitation and production of stents. The present study explores electrochemical polishing of 316L stainless steel slotted tube coronary stents produced by laser cutting. Acid pickling was also studied as a pre-treatment of electrochemical polishing of the stents to remove the slag (oxides) formed in the production of the stents. Meanwhile, removal of the material was measured as well, caused by both acid pickling and electrochemical polishing processes. It is found that the slag formed on the surface of stents due to the laser cutting production process could be removed by means of acid pickling. Electrochemical polishing results in a smooth stent surface. Meanwhile, both acid pickling and electrochemical polishing applied in the present study have a proper removal of the stent material.     

Magnetorheological fluid-based nanotexturing of tool inserts for turning of duplex stainless steel

This paper deals with the study of the nanotexturing process of the cutting tool inserts with the influence of a magnetorheological fluid-based texturing method. The rake and flank surface of the cutting tool inserts were finished with a silicon carbide abrasive mixture of a magnetorheological fluid. Experimentation is conducted with input variables such as voltage, gap width, and polishing time to achieve the desired value of % reduction of surface roughness, polishing rate, andpolishing time. The surface roughness is found to be less than 40?nm for textured and 120?nm for non-textured inserts with a lesser polishing time. A higher polishing rate of the cutting tool inserts is achieved at a working voltage of 36?V and a gap width of 0.75?mm. The machinability characteristics of the nanotextured inserts are based on the cutting force; tool wear is studied for the turning operation of Duplex stainless steel. The tool flank wear is observed to be 0.63?mm, after 13th pass when turned with an unpolished insert and 0.612?mm after the 19th pass with a polished insert. From the results, it is found that the nanotextured inserts could achieve a tool life of 60% higher than the un-textured inserts in machining the duplex stainless steel.     

Pretreatment of stainless steel substrate surface for the growth of carbon nanotubes by PECVD

Multiwalled carbon nanotubes were grown from acetylene and hydrogen gas mixture directly on stainless steel plates by rf powered PECVD and then electric double layer capacitors were fabricated from them without any further treatment. It was found that suitable pretreatment of stainless steel substrates was required for the satisfactory growth of carbon nanotubes on them. In this study substrates were polished, etched in HF solution and then treated with hydrogen plasma before the growth of carbon nanotubes. SEM shows that the surface of the substrate became smooth after polishing. It was severely etched to reveal grains of stainless steel after dipping in HF solution. With hydrogen plasma treatment the grains become more rounded in shape and grew in size. When the grains size was tens of nanometers, carbon nanotubes were grown. Exposing substrates to the hydrogen plasma for 10 min or longer caused the grains to grow larger and the growth of carbon nanotubes became poorer. Carbon nanotubes grown in this study were mutiwalled and curly in shape. Capacitors made from the carbon nanotubes showed initial specific capacitance in the range of 80–100 F/g.     

Metallurgical Analysis of Crack Initiation of Wire-Cut Electrical Discharge-Machined Spline Actuators Made of 17-4 PH Stainless Steel

Spline actuators made of investment cast 17-4 PH (precipitation hardening) stainless steel were found to contain micro-cracks. The cracked actuators were subjected to optical and scanning electron microscopy and hardness testing, which revealed that the failure occurred due to fatigue crack initiation and growth after electrical discharge machining (EDM). The rehardened layer produced by the EDM remained after machining, and the cracks and surface irregularities associated with this layer provided sites for crack initiation and growth, which ultimately caused rejection of parts. Close dimensional tolerances on actuators require post-heat treatment EDM. Thickness of the recast layer was measured to be about 38–55 μm, and precipitation in vicinity of the machined surface is a potential source for corrosion. Post-machining polishing by means of fluidized bed granules was employed to remove recast layer and associated precipitates. Test results proved that removal of surface layers improved the microstructure and the resistance to crack formation. The post-EDM polishing and subsequent annual inspections proved that problem was solved.     

选区激光熔化不锈钢全流程关键问题研究现状与进展

选区激光熔化(SLM)是制造精度最高的金属增材制造工艺,用于制造复杂几何形状的金属零件。316L不锈钢具有面心立方结构,在从熔融态冷却至室温的过程中通常不发生固态相变,基于这种特性,316L不锈钢成为SLM中应用最广泛的金属材料。与传统工艺相比,SLM工艺虽然能够生产高致密、高性能的零件,但是它无法避免孔洞、空隙等缺陷的出现,且存在力学性能差异和需要后处理加工等问题。为了解决这些问题,需揭示SLM制造工艺参数对性能的影响规律。综述了SLM-316L制备全流程前、中和后期在原始粉末、工艺参数及后处理方面的研究现状,首先讨论了粉末质量指标及制粉工艺对不锈钢制件的影响机理;其次总结了激光输入功率、扫描速度等工艺参数对制件性能影响的研究现状;最后对表面机械磨损处理、电解抛光等后处理方式及制件性能影响规律做了简要总结。阐明了通过SLM影响因素预测不锈钢成形零件力学性能的学术观点,以期为获取高质量零件、促进不锈钢材料的实际应用提供一些参考。     

Fabrication and Characterization of FeNiCr Matrix-TiC Composite for Polishing CVD Diamond Film

Dynamic friction polishing (DFP) is one of the most promising methods appropriate for polishing CVD diamond film with high efficiency and low cost.By this method CVD diamond film is polished through being simply pressed against a metal disc rotating at a high speed utilizing the thermochemical reaction occurring as a result of dynamic friction between them in the atmosphere.However, the relatively soft materials such as stainless steel, cast iron and nickel alloy widely used for polishing CVD diamond film are easy to wear and adhere to diamond film surface, which may further lead to low efficiency and poor polishing quality.In this paper, FeNiCr matrix-TiC composite used as grinding wheel for polishing CVD diamond film was obtained by combination of mechanical alloying (MA) and spark plasma sintering (SPS).The process of ball milling,composition, density, hardness, high-temperature oxidation resistance and wear resistance of the sintered piece were analyzed.The results show that TiC was introduced in MA-SPS process and had good combination with FeNiCr matrix and even distribution in the matrix.The density of composite can be improved by mechanical alloying.The FeNiCr matrix-TiC composite obtained at 1273 K was found to be superior to at 1173 K sintering in hardness, high-temperature oxidation resistance and wearability.These properties are more favorable than SUS304 for the preparation of high-performance grinding wheel for polishing CVD diamond film.