焊接材料及其生产设备

在低合金钢焊条药皮过渡微量的稀土氧化铈,通过用MATLAB函数辅助计算、曲线拟合,得出氧化铈与熔敷金属力学性能的定量关系公式。结果表明,定量关系公式误差较小,抗拉强度误差由原来的44MPa降为1MPa,下屈服强度误差由原来的100MPa降为2MPa。把稀土元素换算成碳当量,引入低合金钢焊条配方设计公式中,减少了试验次数,降低了焊条设计成本。图6表4参12     

焊接材料及其生产设备

在低合金钢焊条药皮过渡微量的稀土氧化铈,通过用MATLAB函数辅助计算、曲线拟合,得出氧化铈与熔敷金属力学性能的定量关系公式。结果表明,定量关系公式误差较小,抗拉强度误差由原来的44MPa降为1MPa,下屈服强度误差由原来的100MPa降为2MPa。把稀土元素换算成碳当量,引入低合金钢焊条配方设计公式中,减少了试验次数,降低了焊条设计成本。图6表4参12     

氧化铈对低合金钢焊条焊缝硫磷的影响

试验中在E5515—G型低合金钢焊条药皮中过渡了不同含量的稀土氧化铈,目的是提高焊条性能.采用的试验有焊接接头冲击韧度试验,焊缝金属金相组织试验,X射线荧光光谱试验.结果表明,加入适量的氧化铈能够对焊缝进行脱硫、脱磷,提高熔敷金属的冲击吸收功.氧化铈的加入量不同,脱硫效果不同,且差异较大,而脱磷效果并不十分明显.药皮中加入氧化铈可以细化焊缝组织,但氧化铈的加入量应适当.当氧化铈加入量为3%时,焊缝的组织最细小.当氧化铈加入量最佳时,焊缝金属硫的减少量可达58.13%,而磷的减少量为14.29%.     

低合金钢用湿法水下焊条的研制及应用

研制了一种低合金钢用抗拉强度为530MPa级湿法水下焊条。本文就焊条的药皮设计、防水涂层选择、焊条的各项性能及其与英国HydroweldFS水下焊条的比较作了介绍。该焊条已经在桥梁和港口设施等海洋工程中获得应用。     

低合金钢用湿法水下焊条的研制及应用

研制了一种低合金钢用抗拉强度为530MPa级湿法水下焊条。本文就焊条的药皮设计、防水涂层选择、焊条的各项性能及其与英国Hydroweld FS水下焊条的比较作了介绍。该焊条已经在桥梁和港口设施等海洋工程中获得应用。     

低合金钢焊条熔敷金属机械性能与成分间的相关性分析

建立了低合金钢焊条熔敷金属机械性能与其成分间的数学模型,给出了能够直观、定量反映合金元素对机械性能影响规律的三元等值线图。该图可以预报和优化熔敷金属的机械性能。因此对设计低合金钢焊条具有指导意义。     

成都市焊接学会 四川省水电厅机修厂锅炉、压力容器焊工考试试题摘登

一、下列各条哪些是正确的? 1.焊前预热的主要目的是改善热循环,防止冷裂缝。 2.按含合金元素总量,合金钢可分为低合金钢和中合金钢两大类。 3。电弧的静特性曲线是电源输出电流和输出电压的关系曲线。 4.直流反极性是工件接正极。用低氢型焊条焊接低合金高强钢时,一般选用直流正极性。 5.通常碳素钢按抗拉弧度选用焊条,低合金钢技屈服强度选用焊条,而耐热钢和不锈钢按化学成分选用焊条。 二、填空题 1。碳素钢和低合金钢常用的碳当量公式为:()。 2.AI一1焊工合格证的含义是()。 3.焊接线能量的公式为(),其中电流的单位是(),电压的单位是()…     

稀土氧化物对碱性焊条工艺性能的影响

通过正交实验方法设计九组以稀土氧化物为添加剂的碱性焊条药皮成分,研究了在焊条药皮中添加的稀土氧化物种类和添加量对焊条的断弧长度、脱渣率和飞溅率的影响.结果表明.适量氧化镧、氧化铈和氧化钇的混合添加剂具有提高碱性焊条的电弧稳定性和脱渣率及降低飞溅率的作用.其中添加0.7%氧化镧、0.7%氧化铈和1.0%氧化钇的焊条综合工艺性能相对最好:氧化镧、氧化铈和氧化钇对焊条工艺性能的影响规律和作用程度均不同.但无显著差异.     

稀土氧化物对低合金钢焊缝组织与韧性的影响

通过正交试验方法设计9组以稀土氧化物为添加剂的碱性焊条药皮成分,研究了在焊条药皮中添加的稀土氧化物种类和添加量对低合金钢焊缝组织与低温韧性的影响。试验结果表明,适量氧化镧、氧化铈和氧化钇的混合添加剂具有改善焊缝组织和提高焊缝低温冲击韧性的作用,在药皮中添加w(La2O3)0.7%,w(Ce2O3)1.0%和w(Y2O3)0.3%时,其焊缝低温韧性相对最好;氧化钇对焊缝低温韧性的影响程度明显高于氧化镧和氧化铈,而氧化镧和氧化铈对焊缝低温韧性的影响规律和作用程度基本相同。     

信息动态

制备了常用焊接方法3种组合下的低合金钢表面不锈钢堆焊层试板:单层带极埋弧堆焊、双层带极埋弧堆焊以及单层带极埋弧堆焊+焊条电弧焊堆焊,并分析了3种组合下低合金钢热影响区的金相组织.结果表明:单层带极埋弧堆焊和单层带极埋弧堆焊+焊条电弧焊堆焊2种组合下低合金钢热影响区存在明显粗晶区,双层带极埋弧堆焊后低合金钢热影响区粗晶区明显被细化.     

Evaluation of Crack-tip Stress in Titanium Oxide Film Using Piezo-spectroscopy Methods

The biaxial piezo-spectroscopic coefficient of 530 nm cathodoluminescence band of polycrystalline anatase titanium oxide film was measured using a local calibration procedure. Firstly, the crack-tip stress intensity factor in titanium oxide was measured from the crack opening displacement of a Vickers indentation crack using both Irwin‘s formula and Fett‘s formula, and the validity of these two formulas was evaluated. The obtained value was about Ktip =1 MPa√m， In such a brittle material, the fracture toughness can be considered to be very close to the stress intensity factor measured in an equilibrium indentation crack (Ktip= Kc). From the Ktip value, we calculated the stress distribution ahead of the crack tip using principles of linear elastic fracture mechanics. An important finding was that the cathodoluminescence 530 nm band that originated from excitons self-trapped on TiO6 octahedra, is sensitive to stress. Using the shift of this peak and the calculated stress from linear elastic fracture mechanics, the biaxial piezo-spectroscopic coefficient of this band was determined (40 nm/GPa with a 20% error rate). Using this piezo-spectroscopic coefficient, approximate stress maps can be collected of unknown stress fields within thin films with high spatial resolution into the scanning electron microscope. The present experiments provide a vivid example of quantitative micromechanical stress analysis by piezo-spectroscopic techniques.     

Effect of Cerium on High-Temperature Oxidation Resistance of 00Cr17NbTi Ferritic Stainless Steel

The influence of cerium addition on the isothermal oxidation behavior of 00Cr17 NbTi ferritic stainless steel was studied at temperature up to 1,000 °C for 100 h in air. The results show that cerium additions can reduce the grain size of this ferritic stainless steel, improve the diffusion of chromium and decrease the critical concentration of chromium to form protective Cr2O3 layer. With the increasing of cerium addition, the oxide particles become smaller and this can increase the rupture strength and spalling resistance of oxide layers. The transport mechanism through the oxide layer is varied from metal transport outward from steel to principally oxygen transport inward with the increase of cerium content,which leads to the lower oxidation rate and the better scale adherence of 00Cr17 NbTi ferritic stainless steel.     

高速电弧喷涂不锈钢涂层的旋转回归试验研究

对比研究了３Ｃｒ１３不锈钢高速电弧喷涂涂层和普通电弧喷涂层的孔隙率、氧化物含量、涂层结合强度和滑动磨损性能,并采用多因素正交旋转回归设计和单因素对比试验的方法了高速电弧涂工艺参数对３Ｃｒ１３不钢涂层显微硬度的影响,用微机回归得到了喷涂工艺参数与涂层硬度之间的定量关系式。结果表明,和普通电弧喷涂涂层相比,高速电弧喷涂涂层组织致密、孔隙度低、涂层氧化物含量增多,涂层－基体界面结合强度大于４０ＭＰａ,比     

高频电刀电凝模式下304不锈钢和钨两种电极表面的组织粘附行为

为探索电极材料熔点对电极表面组织粘附的影响,采用不同熔点的电极材料(304不锈钢和钨)对离体猪肝脏组织进行电切割试验,研究了电凝模式下电极表面的组织粘附行为。结果表明,在电切割过程中,低熔点的304不锈钢电极表面发生显微熔融、导致电极表面粗糙化,电极基体元素在粘附组织-电极界面出现扩散,粘附组织结合强度大于4.11 MPa;而高熔点的钨电极表面形态无明显变化,电极基体元素在粘附组织-电极界面没有出现扩散,粘附组织结合强度约1.65 MPa。进一步研究发现,钨电极表面粗糙度越大,粘附组织的结合强度越大,这间接证实电切割过程中304不锈钢电极表面显微熔融导致的表面粗糙化是其表面粘附组织结合强度明显大于钨电极的主要原因之一。可见,采用高熔点的电极材料能够避免电极表面显微熔融,从而减轻电极表面的组织粘附。     

CeO2掺杂对ZrO2-Y2O3纳米涂层性能的影响

在45钢基体表面等离子弧喷涂制备了掺杂不同含量CeO2纳米ZrO2涂层,运用XRD,SEM对涂层的组织结构进行了分析,测试了涂层的结合强度和显微硬度,考察了涂层与铝青铜对磨时的摩擦磨损性能．结果表明,CeO2增加了ZrO2涂层的致密性、结合强度和显微硬度．纳米ZrO2涂层中加入CeO2后,增加了ZrO2涂层／铝青铜摩擦副的摩擦系数,增强了纳米ZrO2涂层,耐磨能力．涂层与铝青铜对磨时,随着CeO2含量的增加,ZrO2涂层粘着磨损形式增强,而涂层脆性断裂脱落的趋势减轻．     

Cerium Oxide Film Prepared from Molten Salts

Cerium oxide film is used in many fields,such as corrosion and protection, cell, high-temperature condition, superconductor, catalyst,electronic equipmeflt and meter indication. Nonaqueous oxide film is needed under many actualsituations. Oxide film prepared by electrochemical deposition in aqueous solution, however, isat least partly hydrated. Though dehydration canbe realized by heat tramment, the quality of thefilm will be apparently abased because of the afresh arrangement of atom/molecula…     

Microbridge testing of silicon oxide/silicon nitride bilayer films deposited on silicon wafers

The present work further develops the microbridge testing method to characterize mechanical properties of bilayer thin films. We model the substrate deformation with three coupled springs and consider residual stress in each layer to formulate deflection versus load under large deformation, resulting in a closed-form formula. If the mechanical properties of one layer are available, the closed formula is able to simultaneously evaluate the Young's modulus and residual stress of the other layer, and the bending strength of the bilayer films from the microbridge test. The analytic results are confirmed by finite element calculations. Using a load and displacement sensing nanoindenter system equipped with a microwedge probe, we conduct microbridge tests on low-temperature silicon oxide/silicon nitride bilayer films prepared by the microelectromechanical technique. The experimental results verify the proposed method, yielding the Young's modulus of 41.00±3.60 GPa, the residual stress of −180.88±7.90 MPa and the bending strength of 0.903±0.111 GPa for the low-temperature silicon oxide films.     

X80管线钢在线用焊条的研制

研制了一种X80管线钢在线用碱性低氢焊条,此焊条主要用于X80管线钢管管对接环焊缝打底焊及管线钢的焊补.确定了焊条药皮各组分的合理配比,合理选择焊芯并进行了一系列焊接试验及焊接接头力学性能和金相测试.结果表明,所研制焊条引弧及稳弧性能良好、飞溅小、脱渣好,焊道成形良好;B焊条焊接接头力学性能优异,屈服强度达640 MPa,抗拉强度达804 MPa,冲击吸收功达120 J;B焊条所得焊缝组织为针状铁素体和粒状贝氏体,其比例恰当,与母材组织匹配较好.     

灰铸铁电渣重熔过程石墨球化现象的研究

实验证明,采用高Ｓｉ含量铸铁自耗电极和含稀土氧化物的ＣａＦ２基熔渣,在直流反极性电渣重熔条件下,可制得球墨铸铁,铸铁中石墨球化现象是铁水经电化学变质处理的结果,熔渣中Ｍｇ１Ｃｅ阳离子在渣－金界面阴极区被还原进入铁水熔池,起到球化剂的作用,提高阳极区自耗电极中的Ｓｉ含量,可以抑制渣中Ｆｅ阳离子的形成,有助于上述电池化学还原反应的进行,这对建立新的冶金工艺技术有一定意义。     

Enhancement Mechanism of Cerium in 316LN Austenitic Stainless Steel During Creep at 700 °C

Effect of cerium (Ce) on creep strength and microstructure of 316LN austenitic stainless steel (316LN steel) at 700 °C/150 MPa was investigated by scanning electron microscopy (SEM), scanning transmission electron microscopy (STEM) and thermodynamic calculations. Addition of 0.032 wt% Ce to 316LN steel results in a prominent increase in creep life from 313 to 556 h. Ce enriches in titanium nitride nanoparticles, increases slightly the activity and diffusion coefficient of Mo, and facilitates the formation of fine and dense intragranular Laves phase precipitates. Thus the creep strength is remarkably enhanced by Ce addition in 316LN steel through the intragranular Laves phase precipitation strengthening. It reveals a new insight into the improvement effect of rare earth (RE) elements such as Ce on creep strength of austenitic stainless steels, which inspired the design of RE-microalloying heat-resistant steels.