预先冷轧变形对马氏体时效钢强化的影响

系统研究了预先冷轧变形对马氏体时效钢强化的影响,研究结果表明:510℃×3 h时效引起的强度净增加值恒定,与冷轧变形量无关,最终的强度为:σ=σ0 △σCR △σAge,即初始强度、冷加工强化和时效强化的叠加,其中只有冷加工强化△σCR随变形量变化.电子衍射花样及衍射斑强度分布证实:510℃×3 h时效后马氏体基体内析出六方结构的Ni3(Ti,Mo)和正交结构的Ni3 Mo,冷轧变形量对时效析出行为没有明显的影响.     

Y2O3–CeO2双相弥散强化对Mo合金晶粒度及拉伸性能的影响

采用纳米喷雾掺杂技术和粉末冶金方法制备了含不同质量分数氧化钇（Y₂O₃）和氧化铈（CeO₂）的Mo–Y–Ce合金,分析了Y₂O₃和CeO₂双相弥散强化对Mo合金晶粒度和室温力学性能的影响。结果表明,Y₂O₃可抑制个别晶粒异常长大,并具有沉淀强化效果。Mo–Y合金丝的力学性能与Y₂O₃掺杂量密切相关,当Y₂O₃质量分数为0.60%时,?1.8-mm Mo–Y合金丝抗拉强度为1050 MPa,屈服强度为923 MPa;CeO₂因与Mo基体具有半共格关系而具有较好的韧化效果,当CeO₂质量分数为0.06%～0.08%时,Mo–Y–Ce合金烧结态晶粒尺寸达10 μm以下,?1.8-mm Mo–Y–Ce合金丝抗拉强度为1130 MPa,屈服强度为1018 MPa,延伸率达到28.5%。?0.18-mm Mo–Y–Ce合金丝抗拉强度达2510 MPa。实验优化出Mo–Y–Ce双相弥散强化Mo合金的最优成分为Mo–0.6Y₂O₃–(0.06~0.08)CeO₂。     

注射成形含氮无镍不锈钢的研究

为了扩大不锈钢的应用范围与节省较昂贵的镍资源,笔者以粒径<38.5μm含氮不锈钢粉末和多组元粘结剂(PW,HDPE,SA)为原料,采用粉末注射成形工艺制备了0Cr17Mn12Mo2N含氮无镍奥氏体不锈钢材料,并对其表面状态与显微组织、拉伸断口形貌以及力学性能、耐蚀性能进行了分析与测试.结果表明:使用上述粘结剂能够成功地实现含氮不锈钢粉末的注射成形;在流动N2气氛中,0.1MPa,1340℃下烧结120min,再经热处理后,注射成形0Cr17Mn12Mo2N不锈钢烧结体的相对密度可达到97.6%,含氮量达到0.83%(质量分数).该含氮无镍不锈钢具有良好的强度和塑性:抗拉强度σb=910MPa,屈服强度σ0.2=560MPa,伸长率δ5=46%,断面收缩率Ф=39.5%,硬度(HRB)为91.7,各项性能指标均优异于MIM 316L不锈钢.     

IC引线框架用高强高导Cu-Cr-Zr合金时效特性研究

利用力学性能测量和透射电镜观察分析等手段，研究了固溶、时效热处理制度对Cu-Cr-Zr合金组织和性能的影响，讨论了合金强化和高电导的机制。结果表明：Cu-0．55Cr-0．15Zr（ω／％）合金经固溶淬火、70％冷轧、450℃ 4h时效后，σb=495MPa、σ2=420MPa、δ=17．5％、相对电导率81％IACS，合金高强高导。     

7NO1铝合金高速反向挤压实验研究

对中强焊接结构材料7NO1铝合金进行了高速反向挤压实验，研究了挤压方式、挤压温度、挤压速度对合金成型过程以及组织性能的影响。研究发现：采用反向挤压，控制合理的挤压温度，可以使挤压速度提高到27．6m／min,此时制品仍不出现周期性裂纹。试样通过后续热处理工艺，组织中析出了弥散的峨强化相。其机械性能达到σb=516．7MPa，σ0．2=450．8MPa，δ=10．6％。     

铁基温压烧结材料性能

研究了烧结密度、合金元素及其含量对铁基温压烧结材料性能的影响。结果表明, 温压铁基合金材料强度和硬度随着密度的增加不断上升。不同Ni含量的Fe xNi 0.5Mo 1Cu 0.5C(x=1.5、2、2.5、3、4)系合金的密度增加到7.45 g/cm3 左右时, 其烧结强度和硬度分别达到1 225~1 389 MPa和HB200~HB350。不同Cu含量的Fe xCu 0.5C(x=1、2、3)系合金的密度增加到7.45 g/cm3 左右时, 其烧结强度和硬度分别达到1 000~1 114MPa、HB150~HB200。Ni、Mo等合金元素具有优异的烧结强化效果。     

超高碳钢的回火组织及力学性能

用CM200型透射电子显微镜研究了超高碳钢双相区淬火 中、高温回火后的组织,用Instron型拉伸试验机测定了力学性能.结果表明:650℃的回火组织为等轴状的铁素体与球状的渗碳体,屈服强度σ0.2=1127MPa,抗拉强度σb=1 266 MPa,均匀伸长率δu=8.26%,总伸长率δt=9.71%,维氏硬度HV为397;450℃回火组织的铁素体保持淬火的形态,回火碳化物为ε碳化物在基体上以断续的片状析出,σ0.2=1 911 MPa,σb=2 028MPa,δu=δt=1.88%,HV为595;400℃回火组织中的铁素体保持淬火的形态,回火碳化物在位错处几乎呈网状析出,拉伸无塑性,HV为703.     

以不同酚醛树脂制备的C/C-SiC复合材料的力学性能

选用热固性酚醛树脂A和热塑性酚醛树脂B分别与短炭纤维、石墨粉、硅粉、碳化硅按一定比例混合后,采用温压-原位反应法,制得具有不同树脂炭基体的C／C-SiC复合材料的试样1和2,并对其力学性能进行研究,以期优化该复合材料的成分配方和进一步提高其技术性能。结果显示：试样1在垂直于纤维层方向的压缩载荷及弯曲载荷作用下,未出现纤维拔出、脱粘等现象,界面结合较强,呈现脆性断裂,压缩强度σ⊥=60．7MPa,弯曲强度σb=34．5MPa;而在平行于纤维层的压缩载荷作用下,纤维与基体存在剪切作用,出现纤维脱粘,呈现韧性断裂,σ∥=52．6MPa。试样2由于纤维的分散性不好,大量聚集在一起,在压缩和弯曲载荷作用下,均存在纤维的拔出和脱粘现象,界面结合较差,材料呈现韧性断裂,强度较低,σ⊥=45．8MPa,σ∥=19．4MPa,σb=16．1MPa。     

wx60,wx65级管线钢的显微组织和强度

武钢研制试生产了用在石油管的含Nb微合金化控轧带钢,该钢冶炼轧制工艺简便,性能较稳定,易于组织生产。对大生产样品,利用金相、透射电镜、特征X射线能谱等手段对带钢的显微组织作了观察,对晶界强化,沉淀强化,位错强化等进行了初步分析。带钢的显微组织为细小的铁素体—珠光体,晶粒平均直径5～7μ。珠光体量约10～15％,为退化或球化珠光体形态。晶界上有颗粒状碳化物。基体上有细小NbC沉淀,平均直径约13nm,呈弥散分布、相间沉淀形态及钉扎于位错线上,基体位错密度为1.6×10~9cm~(-2)。铁素体的平均晶粒直径与屈服强度的关系符合HaII-Petch方程σy=σi+ky·d~(-1/2),求得σi=18.8kgf·mm~(-2),ky=2.63kgf·mm~(-3/2)。其中σi=σo+σ_(so)+σ_(ppt)+σ_(dis)为各强化因素的迭加,而σ_o为位错的点阵阻力,σ_(so)为固溶强化项,σ_(ppt)为沉淀强化项,σ_(dis)为位错强化项,测量计算的结果表明,该钢中上述各强化项的值依次为2.0,5.8～6.1,7.1—7.9,3.0kg.mm~(-2),合计σi=(17.9～19.0)kg.mm~(-2)。     

正火及高温回火对低合金高强度铸钢组织与性能的影响

针对铸钢材料在恶劣环境(重载、低温等)下具有高强度、良好的低温冲击韧性和焊接性的使用要求,设计了1种低碳(w(C)为0.11%),含Ni、Mo的低合金高强度铸钢,重点研究该铸钢经880℃正火+520~650℃回火后的组织与力学性能。结果表明:实验铸钢经正火+回火处理后,由铸态粗大的亚共析组织转变为细小的铁素体+回火贝氏体,铸钢的综合力学性能显著提高;铁素体+贝氏体的混合组织具有高回火稳定性,与添加的Cr、Mo、V等合金元素有关;少量合金元素V在回火过程中形成弥散的(Ti,V)(C,N)析出相,起到析出强化作用;在580℃回火时,σb=590 MPa,σ0.2=470 MPa,伸长率为26%,断面收缩率为70%,尤其是冲击功AkU(室温)与AkU(40℃)分别达到150 J和110 J,室温及低温冲击断口均存在大量的韧窝和撕裂棱,断裂机制为韧性断裂。可见,实验铸钢表现出良好的综合性能匹配,能满足材料在苛刻条件下的使用要求。     

China's Major Non-ferrous Metals Imports & Exports

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Zinc Production by Province in 2014

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80% of Chinese Firms Purchasing Overseas Mines Ended up in the Red

<正>Minmetals Resources acquired the world’s largest copper mine under construction for USD5.85 billion.One after another,listed companies Jien Nickle,China Molybdenum and Chihong Zinc and Germanium raised money to get involved in overseas mining projects…SOEs and private enterprises are engaged in a frenzy of overseas mine purchasing.A reporter with Economic     

Copper Processing Profit Dropped Sharply,Copper Consumption Will Face Impact in the Second Half of the Year

正Judging from China’s copper consumption field,the biggest consumption unit is electric power,which accounts for 47%of total consumption;it is followed by light industry sector,including household electrical appliance,machinery,durable goods and hardware etc,which accounts for 22%of total consumption;followed by transportation field,     

Central Geological Prospecting Fund Newly Added 16.47 Million Tonnes of Bauxite in 2013

正In 2013,the Central Geological Prospecting Fund(CGPF)Project newly discovered 15 ore fields,including 3 large above ore fields,and 5medium sized ore fields.The reporter learned from the recently published"Annual Report of Central Geological Prospecting Fund Project(2013)"that,from 2006 to 2013 the CGPF     

Manufacturers of Copper Tube for Central Air Conditioner Use Face Mounting Pressure in the Final Quarter of the Year

正This year,the investment growth rate of real estate industry continued to slow down,sold area of commercial housing also dropped significantly,which brought huge pressure to the domestic air conditioning manufactures.In the first half of the year,by relying on high growth in national financial expenditure,along with investment in public infrastructure     

Xinjiang Ranks No.1 in Production of Primary Aluminum in China

正Kang Yi,Honorary Chairman of China Nonferrous Metals Industry Association,said recently at the Forum on Development of the Non-ferrous Metals Industry in Central and Western China held in Zhengzhou that,as more and more electrolytic aluminum factories in Xinjiang came into operation,the electrolytic aluminum output of Xinjiang had reached2,275,000 tons in the first 7 months this year,     

Shenhuo Coal Industry and Electricity Power Completed800,000 t/a Aluminum Project in Xinjiang

正"Xinjiang project has been completed according to schedule,but total completion and total start of production are two different concepts,after completion it still needs a gradual process of reaching production target."On the morning of November 3,Shenhuo Coal Industry and Electricity Power told investors the above statement on the investor interaction platform.     

Guangdong Metal Transaction Center has Become the Second Largest Precious Metal Transaction Platform Nationwide

正The reporter learned from Guangdong Province Precious Metal Transaction Center that in 2013the Center maintained healthy development momentum,and had become the second largest precious metal transaction platform in China in terms of market size;currently Guangdong is quickening steps of financial innovation for the Center,aiming to build a transaction center with international core competitiveness.     

Seven Rare Earth Projects Involving Close to 3 Billion Yuan Investment Landed In the HighTech Zone

正On May 22,Baotou Rare Earth Industry Cooperation Consultation MeetingProject Agreement-signing Ceremony was held in Ningbo,nearly 40 enterprises from Ningbo,Guangdong,Hunan,and Shanxi participated in project consultation.After multi-lateral communication,agreements were signed for a total of 7 rare earth projects successfully.