Structure of low cobalt Fe-Cr-Co-based alloy for permanent magnets

Results of an experimental research into evolution of structure and micro hardness hard magnetic alloy Fe-30Cr-8Co-0.7Ti-0.5V-0.7Si at complex two-level in isothermal conditions on the circuit deposittorsion at various temperatures in single-phase ( are given. It is revealed that deformation results in transformation of coarse-grained structure in fine-grained in all volume of the sample, however the generated structure is non-uniform on section of a sample. In an active zone of deformation near to mobile it is brisk the microcrystalline layer with the size of grains about 5 microns which thickness poorly depends on temperature is formed. In process of removal from an active zone of deformation the size of grains is increased, and micro hardness decreases.     

碘量法测定钴铬烤瓷合金中的钴

采用碘量法测定钴铬烤瓷合金中的钴,测定结果的相对标准偏差(RSD)为0.11％(n=11).表明该方法具有良好的精密度,准确度高,能够满足钴铬烤瓷合金中钴含量的测定要求.     

Microstructure of low cobalt FeCrCo hard magnet alloys

The alloys of system Fe-Cr-Co concern to group hard magnetic materials of dispersion-hardening class.……     

Microstructure of low cobalt FeCrCo hard magnet alloys

The alloys of system Fe-Cr-Co concern to group hard magnetic materials of dispersion-hardening class.     

复杂低硫铜钴矿加压浸出提钴工艺研究

以吉林某低硫铜钴矿为例,采用加压浸出技术,不加入黄铁矿或硫磺,实现反应自热进行,使钴铜镍的浸出率达到98%以上。铁、钙、镁、硅进入渣相,无二氧化硫产生。     

低合金贝氏体铸钢的研究和应用

以Si、Mn、Cr为主要合金元素 ,加入少量Mo、V、Ti、B、Y进行微合金化和变质处理 ,在空冷淬火条件下 ,获得了综合性能优良的贝氏体组织 ,用于制造研磨煤粉的破碎机锤头和球磨机衬板 ,使用寿命比高锰钢提高 3～ 5倍 ,可明显提高研磨设备运转率 ,降低煤粉研磨成本     

Influence of HVOF coating on the HCF of 300M low alloy steel

The ultimate methods for solving the contamination of Cr6+ is to replace the Cr electroplating with other techniques, thermal spray provides one of the best choices among those alternative techniques. The influence of coatings upon the fatigue performance of substrate, however,should be labeled as an important factor at some high level applications. The effects of both coatings manufactured by HVOF and Cr electroplating respectively on the fatigue performance of substrate are investigated in this article. These results show that the fatigue limit strength at P= 50 %of thermal spray coating is 750 MPa in comparing with fatigue limit 726 MPa for substrate, and the fatigue life increase 25%- 150% when comparing with fatigue life of substrate at different stress levels. The fatigue life increases in the stress scope of 750-850 MPa even the area of thermal spray coating is subtracted. Cr eleetroplating coating reduces the fatigue life by 70%- 95% and the fatigue limit is only 600 MPa. Fracture analysis reveals that the main fracture is initiated at the subsurface, which is 0.2-0.5 mm away from substrate surface. The analysis also observes that the crack in the Cr electroplating propagates through the interface and finally into the substrate which hastens the formation of crack origin and the extension of crack in the substrate, however, the crack in the thermal spray coating deflects at the interface, spreads along the interface, as a result,the crack forming in the coatings has no negative influence on the main crack initiator and crack extension in the substrate.     

Influence of HVOF coating on the HCF of 300M low alloy steel

1IntroductionLanding gear is easily worn due to its action with ground during landing and takeoff,and traditionalabrasive-resistance methodis the Cr electroplating technology.Cr is deposited owing to the oriented move-ment of Cr2O7-to the cathode of D.C.where electrochemical reactions take place.The technology is fea-tured as si mplicity,lowcost,high hardness,good abrasion-and corrosion-resistance andis widely appliedin many industries.However,Cr electroplating technique will let off carcin…     

Influence of HVOF coating on the HCF of 300M low alloy steel

The ultimate methods for solving the contamination of Cr6+ is to replace the Cr electroplating with other techniques, thermal spray provides one of the best choices among those alternative techniques. The influence of coatings upon the fatigue performance of substrate, however,should be labeled as an important factor at some high level applications. The effects of both coatings manufactured by HVOF and Cr electroplating respectively on the fatigue performance of substrate are investigated in this article. These results show that the fatigue limit strength at P= 50 ,of thermal spray coating is 750 MPa in comparing with fatigue limit 726 MPa for substrate, and the fatigue life increase 25,- 150, when comparing with fatigue life of substrate at different stress levels. The fatigue life increases in the stress scope of 750-850 MPa even the area of thermal spray coating is subtracted. Cr eleetroplating coating reduces the fatigue life by 70,- 95, and the fatigue limit is only 600 MPa. Fracture analysis reveals that the main fracture is initiated at the subsurface, which is 0.2-0.5 mm away from substrate surface. The analysis also observes that the crack in the Cr electroplating propagates through the interface and finally into the substrate which hastens the formation of crack origin and the extension of crack in the substrate, however, the crack in the thermal spray coating deflects at the interface, spreads along the interface, as a result,the crack forming in the coatings has no negative influence on the main crack initiator and crack extension in the substrate.     

氧压酸浸在含锗铜钴白合金有价组分分离中的应用

以国外某含锗、镓的铜钴白合金为原料,采用硫酸氧压酸浸工艺分离合金中有价组分.试验结果表明:与常压氧化酸浸相比,氧压酸浸可以显著提高白合金中有价组分的分离效率.在常温常压预浸2h,再150℃氧压浸出4h,合金中铜、钴浸出率可分别达到97.％和98.24％;锗、镓铁共存于铁红渣中,渣中铜、钴含量可降到0.2％～0.4％,实现了铜、钴与锗、镓、铁的分离.     

New energy vehicle:an opportunity for rare earth magnets

<正>Extracted from Securities Guide 1.Popularity of new energy vehicles—an irresistible market trend1.1 Progress of new energy vehicles Chinese Premier Li Keqiang said recently on a visit to Xi'an BYD Autos that new energy vehicles,especially new energy bus,can lessen environment and noise pollution.He encouraged the use of new     

从钴渣中回收钴的研究进展

钴渣是湿法炼锌净化过程中产生的固体废弃物,常含有钴、锌等有价金属,具有很高的回收利用价值。本文综述了近年来国内外从湿法炼锌净化钴渣回收钴的方法,介绍了氧化沉淀法、选择性浸出法、β-萘酚沉钴法、氨-硫酸铵法、溶剂萃取法的原理,分析了各方法的优缺点和应用前景,认为溶剂萃取法有较好应用前景。     

新版低合金高强度结构钢标准浅析

GB/T 1591《低合金高强度结构钢》是非常重要的钢铁产品标准,其涉及面广、影响面大.最新修订发布的2018版标准与旧标准相比有很大变化.根据新版标准,对其变化较大的内容进行介绍,并与旧标准进行分析比较,以便更好地理解、宣传和贯彻新标准.     

石墨和铜对粉末冶金低合金钢烧结硬化性能的影响

研究了添加石墨和铜对粉末冶金低合金钢烧结硬化性能的影响.结果表明,烧结钢的表观硬度和抗拉强度随石墨和铜含量的增加而增加,但石墨含量过高会导致烧结钢的抗拉强度降低.     

石墨和铜对粉末冶金低合金钢烧结硬化性能的影响

研究了添加石墨铜对粉末冶金低合金钢烧结硬化性能的影响，结果表明，烧结钢的表现硬度和抗拉强度随石墨和铜含量的增加而增加，但石墨含量过高会导致烧结钢的抗拉强度降低。     

双层辉光离子渗Cr合金层组织和性能

在Q235钢表面进行双层辉光离子渗Cr，表面Cr含量约为40％，渗层厚度近50 μm.然后进行超饱和渗C，表面含C量达到2.7％左右，超过平衡碳计算值.随后进行淬火＋低温回火处理，经X射线衍射分析，合金化层碳化物类型为M23C6，M7C3，尺寸为1～2 μm.表面硬度达到HV 1 200左右.将表面冶金试样进行摩擦因数和耐磨性能试验，结果表明，表面冶金试样摩擦因数为0.21～0.28，耐磨性是Q235钢渗碳淬火试样的1.62倍.将表面冶金试样在10％的H2SO4、3.5％的NaCl水溶液和H2S富液（含H2S 5～8 g/L，NH3·H2O 20 g/L）中进行电化学腐蚀试验，结果表明，表面冶金试样在10％的H₂SO₄、3.5％的NaC1水溶液和H2S富液中的耐腐蚀程度比Q235基体试样分别提高了2.35，3.10，2.14倍.     

煤基费托合成催化剂活性组分的选择

对具有费托合成活性的金属元素进行了介绍和分析,并对具有工业应用价值的铁系催化剂和钴系催化剂从催化剂性能特点、所适用的原料气组成、抗毒性能等方面进行了深入比较.认为在现阶段,铁系催化剂更适用于以煤制合成气为气头的间接液化过程.而钴系催化则是低温费托合成技术的发展方向.