INFLUENCE OF ALLOYING ELEMENTS ON HYDROGEN DIFFUSION USING SCM-DV-Xα

The influence of alloy composition (Ti,Mn,TiN) on hydrogen diffusion in Fe was studied in detail using SCM-DV-Xα method.The voltage barriers were obtained via calculation on Fe clusters containing the alloy elements such as Ti,Mn as well as the chemical compound TiN respectively.The results showed that Ti element produced deep trap in Fe,decreasing the diffusion coefficient of hydrogen elements，Mn element did not produce deep trap in Fe,decreasing the diffusion coefficient slightly and TiN in Fe produced very deep “trap” decreasing the diffusion coefficient obviously.The calculation results were in agreement with experiment results.     

α-Fe中置换式合金元素的氢陷阱效应SCIEI

用电化学渗氢方法测定了氢在纯Fe和Fe-Cr,Mn,Co,Si,Mo的二元合金中的扩散系数。结果表明所研究的二元铁基合金中,随着合金元素浓度的增加,氢的扩散系数降低,氢的扩散激活能增加。根据Oriani模型计算了各种合金元素的氢陷阱参数,并获得了相应的氢与陷阱结合能。按陷阱结合能由小到大的顺序是:Si,Co,Ni,Mn,Cr和Mo。最后根据合金元素引起的晶格应变场与氢的弹性交互作用和合金元素与氢的电性交互作用对结合能的本质进行了分析。     

SOLUBILITIES OF Ce,Nd AND Y IN α-Fe

The solubilities of Ce,Nd and Y in α-Fe at 873 to 1153 K have been deter mined by meansof electron microprobe quantitative analyses.The temperature dependences of the solubilitieswere obtained from the experimental data.The results have been compared with those deter-mined by three other technigues,very good agreement was obtained between the results of allthese techniques.     

SOLUBILITIES OF Ce, Nd AND Y IN α-Fe

用电子探针定量分析法测定了Ce、Nd和Y在873到1153K之间在α-Fe中的溶解度,从而获得溶解度与温度的关系式 用x射线衍射法测定样品的点阵常数,用正电子湮没法测定Doppler线形参数S以及合金的矫顽力,用这三者与合金中稀土元素含量的关系确定稀土元素在α-Fe中溶解度的几个实验点。对上述电子探针测定的结果进行校核,其一致性令人十分满意     

EFFECT OF ALLOYING ELEMENTS ON γ′SOLVUS TEMPERATURE OF Ni-BASE SUPERALLOYS

配制了38种复杂成分镍基实验合金,测定其γ′固溶温度,利用回归分析方法确定了γ′固溶温度和合金元素间的定量关系并对合金元素的影响进行了评论。用所得的γ′固溶温度线性方程对13种典型商用镍基高温合金进行预测,计算结果与实测数据基本一致。     

DIFFUSION OF HYDROGEN IN (α+γ) DUPLEX STAINLESS STEEL

采用电化学渗透方法,测定了氢在(α+γ)双相不锈钢中的扩散渗透曲线。氢的表观扩散系数与奥氏体含量(f_γ)的关系为:D=0.27+0.9/f_γ~2(10~(-10)cm~2/s),初步证明氢在(α+γ)双相不锈钢中主要是通过α相和γ相“串联”扩散,扩散系数D≈D_αD_γ/(f_γ~2D_α+f_α~2D_γ),其中D_α,D_γ分别为氢在α相和γ相中的扩散系数,f_α,f_γ分别为α和γ相的体积分数。     

EFFECT OF HETEROGENEOUS DISTRIBUTION OF C AND ALLOYING ELEMENTS ON γ/α′ TRANSFORMATION IN A Fe-Mn-Cr-C ALLOY

用内转换Mossbauer谱分析了Fe-Mn-Cr-C合金冷变形前后合金元素原子与碳原子的不均匀分布和相组成。发现该合金在固溶处理状态时为两类奥氏体,即无碳奥氏体和含碳奥氏体;经变形诱发出不含碳与合金元素的无碳马氏体(类α-Fe)及含碳与合金元素的合金马氏体。理论计算和试验证实:该合金中奥氏体向马氏体转变是受奥氏体晶胞内共价键中共用电子对的数目(n_A值)大小所控制。合金元素原子与碳原子之间形成结合力较强的C-M_e共价键,这对合金马氏体的形成具有强烈的阻碍作用。     

EFFECT OF HETEROGENEOUS DISTRIBUTION OF C AND ALLOYING ELEMENTS ON γ/α′ TRANSFORMATION IN A Fe-Mn-Cr-C ALLOY

The heterogeneous distribution of C and metallic alloying elements as well as the phase com- position changes before and after cold deformation of an Fe-Mn-Cr-C alloy have been stu- died by the use of Mssbauer spectroscopy.The austenites without and with C and metallic alloying elements are found in the alloy in as-solid solution state.While the martensites with- out and with C and alloying elements may be induced by cold deformation.The transforma- tion from austenite to martensite in the alloy is confirmed via theoretical computation and ex- periments to be controlled by the number of covalent electron pairs forming covalent bond in austenitic crystal cell of the alloy.The formation of strong covalent bond between C and me- tallic elements can vigorously retard the γ/α' transformation.     

MAGNETIC PROPERLIES AND STRUCTURE OF A MIXTURE OF α-Fe and Fe_3N DURING MECHANICAL ALLOYING PROCESS

利用X射线衍射研究了α-Fe与Fe3混合粉末机械合金化过程中结构的变化．并测量了球磨不同时间后其饱和磁化强度的变化结果表明,随着球磨时间的延长,Fe3N相迅速分解直至消失,N原子部分固溶于α-Fe中,24h后可形成稳定的α-Fe（N）过饱和固溶体,其中N的质量分数约为0．290％-0．346％．随着球磨时间的延长,α-Fe的晶粒尺寸逐渐减小,24h后趋于定值,约为8nm．球磨引起样品中Fe原子周围N原子位置的变化,使得球磨过程中混合粉末的饱和磁化强度开始时降低,5h后又有所增加,24h后达到一定值     

MECHANISM FOR DIFFUSION OF BORON IN γ-Fe

Mechanism for diffusion of B in γ-Fe is believed to be mainly by means of boron-vacancycomplexes other than as interstitial atoms previously.This was made of calculation on the ba-sis of theoretical model proposed by the authors.The calculated diffusion coefficient of B inγ-Fe after this mechanism is consistent with the experimental values.In addition,this is alsosupported by the non-equilibrium segregation phenomenon of B at grain boundaries of γ-Feand the lattice constant measurement of Fe-B alloy.     

IMPROVEMENT IN TENSILE PROPERTIES OF α+β TYPE Ti ALLOYS BY HYDROGEN TREATMENT

提出了一种新的细化α+β型钛合金显微组织的氢处理工艺:在合金的氢化β转变点以下0—40K的温度范围对合金渗氢处理,空冷至室温,最后在948K真空除氢。Ti-6Al-4V和Ti-5Al-2.5Fe合金经此工艺处理后,组织显著细化,屈服强度,拉伸强度及延伸率分别提高8—15％,5—13％,7—14％。     

EFFECT OF δ-Fe CONTENTS ON HYDROGEN EMBRITTLEMET SUSCEPTIBILITY FOR AUSTENITIC Fe-Cr-Ni-Mn-N STEELS

采用高压气相充氢后进行缺口试样拉伸试验的方法,证实了δ铁素体含量的增加显著提高Fe-Cr-Ni-Mn-N系奥氏体不锈钢的氢脆敏感性.     

MECHANISM FOR DIFFUSION OF BORON IN γ-Fe

实验结果表明,硼在γ—Fe中的扩散系数相当于间隙原子的扩散系数,故一般认为硼是以间隙方式扩散,但本文计算结果表明:硼在γ—Fe中,主要是以硼—空位复合体方式扩散,其扩散系数与实验值非常接近,而且γ—Fe/B晶界的非平衡偏聚和Fe—B系晶格常数测量结果支持了本文的观点。     

EFFECT OF La ON SNOEK-KE-K■STER PEAK IN Fe-P-N ALLOY

研究了F? P—N合金加?对Snoek—Ke-Koster(SKK)峰的影响,发现与合金含La,P的原子浓度比(C_(La)/C_p)有关:对于C_(La)/C_p较大(例如4.56和2.6)的合金,La有明显增强SKK阻?效应:对于C_(La)/C_p=0.27的P过饱和合金,La对SKK峰无明显影响。     

BEHAVIOUR OF α-NITROSO-β-NAPHTHOL IN HEMATITE FLOTATION

Based on theoretical calculation of electronegativity of groups of flotation reagent andmethod of infrared adsorption spectroscopy,the collection and adsorption of α-nitroso-β-naphthol in hematite flotation have been studied.The chemical adsorption seems to bepredominant owing to formation of pentacyclic nitrosyl chelate compound by atoms ofnitrosyl bond in α-nitroso-β-naphthol together with Fe(Ⅲ)on hematite surface.Mean-while,the nonuniform multilayer physical adsorption is also occurred.     

BEHAVIOUR OF α-NITROSO-β-NAPHTHOL IN HEMATITE FLOTATION

研究了α-亚硝基β-萘酚对赤铁矿的捕收性能及吸附规律,导出了吸附方程和吸附速率方程用药剂基团电负性理论计算以及红外吸收光谱法论述了其作用机理α-亚硝基β—萘酚主要是以N O键合原子与赤铁矿表面的Fe(Ⅲ)形成N O五元环螯合物而化学吸附.同时也兼有多层的,不均匀的物理吸附     

EFFECT OF PRESSURE ON GRAIN SIZE OF CRYSTALLIZED PHASE α-Fe(Mo,Si)IN AMORPHOUS (Fe_(0.99)Mo_(0.01))_(78)Si_9B_(13)ALLOYS

在压力为３－６ＧＰａ和温度为７２３－９３３Ｋ范围内，对非晶（Ｆｅ０．９９Ｍｏ０．０１）７８Ｓｉ９Ｂ１３合金等温晶化形成的纳米α－Ｆｅ（Ｍｏ，Ｓｉ）晶粒尺寸随温度和压力的变化进行了研究。发现其晶粒尺寸随压力变化主要取决于压力对成核速率手影响，其根本原因是压力对熔点的作用。     

NdFeB/α-Fe合金快淬薄带表面微观形貌

采用快淬加后续晶化退火方法,制备了NdFeB/α-Fe双相纳米晶复合永磁合金的快淬态和晶化态薄带,用原子力显微镜(AFM)观察了薄带贴辊面和自由面的微观形貌,分析研究了薄带不同表面晶粒尺寸与均匀性的差异。贴辊面快淬时冷却速度快、结晶度高,快淬态主要由非晶体组成,退火时新相的析出以均匀形核的方式成核,晶化态晶粒数量少、平均尺寸(～70nm)大,但晶粒大小均匀。自由面快淬时析出了数量较多、尺寸较大的微晶,退火时以非均匀形核为主,成核率高,晶粒数量多、尺寸小,平均晶粒尺寸(～50nm)小于贴辊面,但由于微晶本身的长大,形成了超过100nm的粗大晶粒,使微观结构的均匀性变差。薄带不同表面微观形貌的差异将会对纳米晶复合永磁材料的磁性能产生直接的影响。     

STRESS CORROSION CRACKING AND HYDROGEN INDUCED CRACKING OF ORDERED B_2－TYPE Fe_3Al

用ＷＯＬ恒位移试样研究了Ｂ_２结构的Ｆｅ_３Ａｌ和Ｆｅ_３Ａｌ＋Ｃｒ的应力腐蚀和氢致开裂．结果表明，水中应力腐蚀的门槛值和裂纹扩展速率均高于动态充氢时的相应值加Ｃｒ能提高Ｆｅ_３Ａｌ的Ｋ_（ＩＣ），Ｋ_（ＩＳＣＣ）和Ｋ_（ＩＨ）．氢致开裂断口随Ｋ_Ｉ下降由解理向沿晶转变，水中应力腐蚀则全是解理断口，这与Ｋ_（ＩＳＣＣ）较高有关．     

EFFECT OF PHOSPHORUS ON SOLIDIFICATION,ELEMENT SEGREGATION AND η-PHASE PRECIPITATION IN GH 761 ALLOY

本文用金相、电子探针等方法研究了磷对ＧＨ７６１合金凝固过程、元素偏析及η相析出的影响。结果表明，随合金中磷含量升高，磷大量地偏析于枝晶间，强烈地降低合金的终凝温度，促进Ｔｉ，Ｎｉ等元素的偏析，抑制Ｍｏ，Ｂ，Ｓ，Ｓｉ等元素的偏析，磷显著地促进η相的析出，降低η相析出温度。