铁素体/珠光体带状组织对L360N管线用无缝钢管冲击性能的影响

分析了L360N管线用无缝钢管在热轧态、920℃正火1h、1150℃均匀化退火3h、1150℃均匀化退火3h+920℃正火1h四种状态下的微观组织和力学性能,并对每种热处理状态下带状组织区域和非带状组织区域进行了对比。发现L360N管线钢中的带状组织可以通过长时间高温均匀化退火消除;其带状组织对拉伸性能影响不明显,但对冲击性能影响较大。     

球化退火及后续热处理对高铬耐磨铸铁组织与性能的影响

研究了球化退火及后续不同的热处理工艺对高铬铸铁材料组织与性能的影响。结果表明,在1 200℃高温退火后,高铬铸铁组织中的碳化物由长条菊花状变为短杆、颗粒状。再经过1 000℃加热4 h空冷淬火、500℃回火后,高铬铸铁的硬度为HRC61、冲击韧性为7.19 J/cm2,耐磨性也得到提高,获得较好的组织、硬度、韧性与耐磨性的最佳配合。     

RM2钢下贝氏体等温淬火工艺研究

RM2钢冲击韧性较差,高速冲击或冲击力大的工况下环境容易开裂。为提升RM2钢冲击韧性,本文利用RM2钢下贝氏体组织具有优良综合强韧性能特点,对不同等温淬火温度处理后的微观组织和力学性能进行了对比分析,优选出最佳工艺参数:1150℃奥氏体化、330℃等温淬火60 min,获得了良好的综合力学性能,硬度可达50.44 HRC、冲击韧性达225.13 J/cm2。     

均匀化退火工艺对铸态Mg-9Gd-3Y-0.5Zr镁合金组织及性能的影响

采用光学显微镜、X射线衍射等研究了均匀化退火工艺对Mg-9Gd-3Y-0.5Zr镁合金组织和性能的影响.结果表明,均匀化退火能有效消除枝晶偏析,改善材料的组织和力学性能;退火温度对均匀化起主要作用.确定了480℃×8h均匀化退火工艺为铸态Mg-9Gd-3Y-0.5Zr镁合金的最佳处理工艺.     

轧制工艺对海洋工程结构用API2W-50钢组织与性能的影响

研究了轧制工艺对海洋工程结构用API2W-50钢组织与性能的影响。结果表明:采用控轧控冷工艺,在1000℃以上和950℃以下分两阶段轧制,终轧温度控制在820℃,轧后水冷至620℃,API2W-50钢的抗拉强度达到540 MPa,伸长率为27%,-40℃纵向冲击韧性可达到279 J,-40℃横向冲击韧性达到215 J,钢板综合力学性能最佳;得到钢组织为贝氏体+铁素体+珠光体,晶粒均匀细小,综合力学性能达到研制目标,具备工业性试制条件。     

热处理工艺对高碳高铬钢组织和性能的影响

研究了不同热处理工艺对RE复合变质高碳高铬合金钢的显微组织和力学性能的影响.研究结果表明:经热处理后组织内残余奥氏体完全分解,转变为粒状珠光体+M7C3型碳化物.高温固溶处理会对共晶碳化物的形态产生影响,随着固溶温度的提高,连续网状的共晶碳化物转变为杆状和块状,使材料的冲击韧性得到提高,球化处理促使基体内大量二次碳化物的析出,大大提高了材料的硬度.适合于高碳高铬合金钢的热处理工艺为1 200℃加热lh固溶,水冷,然后750℃×5 h球化处理.经此热处理后,与铸态实验钢相比硬度提高了30.8％,达到HRC53.9,冲击韧性提高了25％,达到9.5 J/cm2.     

4Cr5W2VSi模具钢的组织及力学性能

对经镦抜锻造的4Cr5W2VSi模具钢进行标准退火和调质处理,沿拔长方向(纵向)和垂直于拔长方向(横向)切取试样进行组织分析、拉伸试验、冲击试验和硬度测试,研究其组织和力学性能。结果表明:退火态组织为粒状珠光体+少量共晶碳化物,调质态组织为回火托氏体+少量共晶碳化物;两种状态均存在偏析,调质处理不能改善带状偏析,带状偏析降低了力学性能。退火态试样的屈服强度、抗拉强度比H13钢提高了45 MPa、90 MPa,塑性略有下降。退火态试样纵向冲击吸收能量为94.3 J,高于横向试样(51 J),存在各向异性;调质态试样纵向和横向冲击吸收能量分别为18.3 J和16.7 J,不存在各向异性,均为脆性断裂。调质态试样的硬度为退火态的3倍左右,其硬度提高是因为生成了脆性托氏体相及二次硬化作用。     

球化温度对4Cr5Mo2V热作模具钢组织和性能的影响

采用光学显微镜和扫描电镜观察了4Cr5Mo2V钢在不同球化温度退火过程中的显微组织变化,利用图像处理软件Image Pro Plus定量分析了碳化物的数量、平均粒径及体积分数,进而研究了球化退火对4Cr5Mo2V钢淬回火状态下力学性能的影响。结果表明,当球化温度在820~900 ℃时,碳化物的单位面积个数、体积分数和平均粒径分别在(10.0~14.0)×10⁸ cm^-2、8.0%~10.0%和0.30~0.43 μm之间。球化温度为840 ℃时,可有效消除不均匀退火组织,碳化物平均粒径为0.31 μm;其室温冲击吸收能量为392 J,具备良好的力学性能。     

退火工艺对铸轧5052铝合金组织和性能的影响

对铸轧5052铝合金板坯进行了的均匀化退火、中间退火和成品退火处理,通过能谱分析、组织观察、维氏硬度和力学性能测试,分析了不同退火温度和时间对合金显微组织和力学性能的影响.实验结果表明,经580℃保温20 h均匀化退火后合金板坯的中间偏析得到有效减轻,组织均匀度得到提高.经420℃保温0.5 h中间退火后,合金板材的塑性得到恢复,利于进一步冷轧加工.对于冷轧板材进行340℃退火,保温1 h后组织处于平衡稳定状态,抗拉强度达到280 MPa,伸长率达到9%.     

两种国内外铝挤模具材料组织和力学性能研究

利用金相显微镜和冲击试验机等研究了两种国内外铝挤模具材料组织和力学性能,对抚顺特钢生产的1.2344钢和ASSAB的8407 2M钢,进行了化学成分、带状偏析、退火组织和冲击韧性对比分析。结果表明:抚顺特钢1.2344钢氧含量和氮含量均高于8407 2M钢,钢材横向截面边部带状偏析优于8407 2M钢,1.2344钢退火组织中存在少量网状碳化物,冲击边部较低与8407 2M钢差距较大。     

Fe-15Ce合金在H2-CO2、H2-H2S及H2-H2S-CO2气氛下的腐蚀

研究了600℃时Fe-15Ce合金在H2-CO2、H2-H2S及H2-H2S-CO2 3种气氛中的腐蚀行为，Fe-15Ce合金腐蚀后发生了Ce的内氧化或形成了复杂的腐蚀产物膜，而未出现Ce的选择性氧化或硫化，这主要是合金中存在着两相及Ce在Fe中极低的溶解度的结果。Fe-15Ce合金在本实验条件下的氧化-硫化腐蚀速度低于相同温度、压力下的纯硫化。     

用氢-氧取代氧-乙炔作焊接切割的必要性及可行性

阐述了用氢代乙炔的必要性．通过时HGQU2000／315火焰电孤焊割机的考察和试用证实了用氢代乙炔的可行性，比较了两种气体的性质并提出了使用特性差异和注意事项．提出了进一步探索的问题。     

Thermodynamics and phase diagrams in the binary systems Na2O-SiO2, Na2O-GeO2, Na2O-B2O3, Li2O-B2O3, CaO-B2O3, SrO-B2O3, and BaO-B2O3

We applied our model to the enthalpy of mixing data of the binary systems Na₂O-SiO₂, Na₂O-GeO₂, Na₂O-B₂O₃, Li₂O-B₂O₃, CaO-B₂O₃, SrO-B₂O₃, and BaO-B₂O₃. The most stable composition in the liquid, that is where the enthalpy of mixing is most negative, is with a metal-oxygen ratio of 4 to 3, for monovalent metals (Na and Li) and 3 to 4 for divalent metals (Ba and Ca) in liquid silicates or borates. The same applies to the CaO-SiO₂, CaO-Al₂O₃, PbO-B₂O₃, PbO-SiO₂, ZnO-B₂O₃, and ZnO-SiO₂ systems. The oxygen to metal ratio, its constant value in various types of systems, reflects and describes the structure of the liquid. Using the analyzed enthalpies of mixing data and the available phase diagrams, we calculated the enthalpies of formation of the various binary compounds. The results are in excellent agreement with data in the literature that were obtained from direct solid-solid calorimetry.     

IrO2-MnO2中间层Ti/RuO2-TiO2-SnO2电极制备及性能

通过热分解法制备了含IrO2-MnO2中间层Ti/RuO2-TiO2-SnO2电极,采用SEM、EDX、XRD、CV等检测方法对中间层进行表征,同时采用强化加速寿命试验对电极电化学稳定性进行表征。结果表明:450℃时前躯体完全氧化并形成固溶体,制备的中间层晶粒细小,表面结构致密,电化学孔隙率小。添加中间层使Ti/RuO2-TiO2-SnO2电极强化寿命由未加中间层的7.5h提高到995.8h,远高于国家标准20h。     

Mechanoluminescence in BaSi2O2N2:Eu

Mechanoluminescence (ML), a general term for the phenomenon in which light emission occurs during any mechanical action on a solid, can be divided roughly into two classes: destructive ML and non-destructive ML. For practical use in high-end applications (e.g. pressure sensors), materials with non-destructive ML properties are preferred. This paper reports on the strong non-destructive ML in BaSi₂O₂N₂:Eu. When irradiated in advance with ultraviolet or blue light, this phosphor shows intense blue-green light emission upon mechanical stimulation such as friction or pressure. The ML has an emission band peaking at 498 nm, which is ～4 nm red-shifted compared to the steady-state photoluminescence. The origin of the ML is discussed and related to the persistent luminescence of BaSi₂O₂N₂:Eu. The same traps are responsible for both phenomena. Based on the occurrence of ML in this phosphor, we were able to show that the predominant crystallographic structure of BaSi₂O₂N₂:Eu belongs to space group Cmc2₁.     

ACTIVITY OF La_2O_3 IN LIQUID La_2O_3-CaF_2 AND La_2O_3-CaF_2-CaO-SiO_2 SLAGS

用石墨为还原剂,将渣中La_2O_3还原入液态Sn,以测定1500℃下La_2O_3-CaF_2和La_2O_3-CaF_2-CaO-SiO_2渣中La_2O_3的活度.对La_2O_3-CaF_2系,并用Gibbs-Duhem积分法求得CaF_2的活度. 根据液态渣的离子结构模型,对上述二渣系中La_2O_3的活度数据进行了简单的讨论.     

氢分子在贮氢材料Li2MgN2H2表面的吸附与解离

采用第一性原理计算方法研究了Li-Mg-N-H体系贮氢材料的放氢产物Li2MgN2H2的吸氢反应过程中的过渡态、表面电子态密度和表面能。结果表明:氢分子在Li2MgN2H2低指数表面中最低能量(100)表面的Mg-Mg-Li穴位吸附位置能够形成最稳定的吸附结构并发生解离,氢分子吸附能为-0.1898eV,解离能约为0.84eV(81kJ/mol),表明该反应所需的反应活化能仍较高,吸氢反应速度缓慢。     

High temperature corrosion of Fe-Cr-Mn-alloys in H2-H2S and H2-H2O-H2S gas mixtures

The sulfidation of Fe-20% Cr-30% Mn, Fe-25%Cr-20%Mn and Fe-25% Cr was studied at 700°C in H₂-H₂S and the oxidation and sulfidation in H₂-H₂O-H₂S after preoxidation in H₂-H₂O. The sulfidation rate is strongly increased for the Mn-containing alloys, layers of (Mn,Cr)S and (Mn,Fe)Cr₂S₄ are formed. Also the oxidation rate is enhanced compared to Fe-25% Cr by formation of MnCr₂O₄ instead of Cr₂O₃. The sulfidation after preoxidation leads to internal and external sulfidation of the Mn-containing alloys. With increasing oxygen pressure p(O₂) = 10^?26…10^?22 atm. of the H₂-H₂O-H₂S mixtures the sulfidation is suppressed, for the higher oxygen pressure 10^?23 and 10^?22 atm. fast oxidation prevails under formation of MnCr₂O₄. Manganese cannot increase the sulfidation resistance of alloys, in spite of the stability and low degree of disorder of its sulfide, since the mixed sulfide (Mn,Cr)S is formed which has a high degree of disorder, high diffusivities and high growth rate according to the doping effect of trivalent Cr³⁺.     

PHASE DIAGRAM OF TERNARY SYSTEM PrCl_2-CaCl_2-MgCl_2

Three surfaces corresponding to the primary crystallization of PrCl_3,CaCl_2 andMgCl_2 respectively,3 univariant curves related to the secondary crystallization and a ternaryeutectic(44.8 wt-% PrCl_3,31.8 wt-% CaCl_2,546℃)were found in systemPrCl_3-CaCl_2-MgCl_2 by means of DTA.A reaction occurs in this system:L=PrCl_3+CaCl_2+MgCl_2.     

Thermodynamic evaluation of phase equilibria in the CaCl2-MgCl2-CaF2-MgF2 system

The phase diagram of the CaCl₂-CaF₂-MgCl₂-MgF₂ reciprocal ternary system was calculated thermodynamically from available data on the common-ion binary subsystems and from available data on the CaCl₂-MgF₂ join. This join is very nearly quasibinary and divides the system into two quasiternary systems: the CaCl₂-MgF₂-CaF₂ system with a ternary eutectic calculated at 724 +-5 °C and the CaC₂-MgF₂-MgCl₂ system with a ternary eutectic calculated at 561 +-5 °C.