汽缸体,汽缸盖用高强度灰铸铁的综合铸造技术

综述了汽缸体，汽缸盖用高强度灰铸铁生产的技术关键和国内外的研究水平，并探讨了我国今后的发展方向。     

大厚度灰铸铁件的焊补

对大厚度灰铸铁件的焊补进行探讨,分析了灰铸铁的焊接性,介绍了栽丝焊和加垫板焊,制定了详细的焊接工艺和操作要点,可用于指导实际操作。     

灰铸铁电弧垫焊和半热焊的工艺特点

焊前将铸件整体或局部预热到600℃-700℃。在焊补过程中保持这一温度。并在焊后采取缓冷措施的工艺方法称为热焊。预热温度在300℃-400℃称为半热焊。     

稀土微合金淬火钢轨接触焊焊后热处理工艺及设备

对稀土粹火钢轨接触焊焊后采用中频感应加热,轨头压缩空气社会火,其他部位正火的热处理工艺。研制了适合于该钢种的加热感应器和高速吹风冷却等装置。通过热模拟试验选择了合理的焊后热处理工艺参数,恢复了轨头强度和硬度,并大幅度地提高了焊接接头的韧塑性和综合性能,满足了无缝线路铺设使用要求。     

轻（微）型汽车发动机铸铁汽缸体的先进铸造法

介绍了汽缸体铸件的技术性能、国内外各大汽车公司和汽车铸造厂所采用的先进铸造方法，这些方法有气冲造型、静压造型、垂直分型无箱射压造型、实型铸造等。提出了批量生产铸铁汽缸体铸件优先采用的铸造方法。     

铸件焊补热处理炉的技术改造

总结了改造焊补热处理炉的经验。通过对燃烧器、炉体、烟道等的改造，减少了热损失，改善了环境条件，提高了产品质量，满足了生产和工艺的要求     

发动机汽缸体中钛化物的测定

本文介绍了Ti元素在气缸体中的存在形式，TiN、TiC硬质点的作用，及测量TiN、TiC硬质点数量的方法。     

汽缸体UT缺陷的产生原因浅析及预防措施探讨

近年来，随着市场竞争的日趋激烈，用户对汽缸体的品质要求越来越严，对交货期要求愈来愈短，而影响生产的主要因素在铸造缺陷的处理，分析了汽缸体铸造缺陷，提出了一些措施。     

热处理对NbVTi合金灰铸铁组织和性能的影响

借助扫描电子显微镜(SEM)和力学性能测试手段,研究了新型贝氏体基体Nb VTi合金灰铸铁经过不同保温时间和温度的热处理后微观组织和力学性能的变化。结果表明:随着保温时间的增长或温度的升高,Nb VTi合金灰铸铁的贝氏体基体组织发生粗化,A型片状石墨厚度和长度增大;拉伸断口呈现准解理断裂特征,并随保温时间或温度的增加出现了一定程度的韧性断裂特征,塑韧性得到改善;随保温时间或温度的增加,Nb VTi合金灰铸铁的抗拉强度和布氏硬度呈下降趋势。     

GH3230合金的焊后热处理

分析测试了GH3230合金氩弧焊接后经不同焊后热处理制度处理后的显微组织、显微硬度和拉伸性能.试验结果表明:GH3230合金焊接板材经1140～1180℃保温10 min焊后热处理,既能使焊后残余应力得到充分释放,又能保证组织稳定,满足合金力学性能要求.     

Structural changes in cast iron cylinder heads

Conclusions It was found that during operation of cylinder heads complex physicochemical processes of internal oxidation occur in the thermally stressed section of the lower wall due to the influence of the exhaust gases. The service life of the cylinder head is determined by the changes in the properties resulting from these processes.Structural changes due to graphitizing of eutectoid cementite were not observed due to the submicroscopic character of such changes and the substantial heterogeneity of the metallic cast iron in the cylinder heads examined.Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 6, pp. 66–67, June, 1970.     

Quantitative models for microstructure and thermal conductivity of vermicular graphite cast iron cylinder block based on cooling rate

The relationships of cooling rate with microstructure and thermal conductivity of vermicular graphite cast iron(VGI) cylinder block were studied, which are important for design and optimization of the casting process of VGI cylinder blocks. Cooling rates at different positions in the cylinder block were calculated based on the cooling curves recorded with a solidification simulation software. The metallographic structure and thermal conductivity were observed and measured using optical microscopy(OM), scanning electrical microscopy(SEM) and laser flash diffusivity apparatus, respectively. The effects of the cooling rate on the vermicularity, total and average areas of all graphite particles, and the pearlite fraction in the VGI cylinder block were investigated. It is found that the vermicularity changes in parabola trend with the increase of cooling rate. The total area of graphite particles and the cooling rate at eutectoid stage can be used to predict pearlite fraction well. Moreover, it is found that the thermal conductivity at room temperature is determined by the average area of graphite particles and pearlite fraction when the range of vermicularity is from 80% to 93%. Finally, the quantitative models are established to calculate the vermicularity, pearlite fraction, and thermal conductivity of the VGI cylinder block.     

灰铸铁件激光熔覆NiCuFeBSi合金的气孔行为

通过对比分析45钢与HT250两种基体成形熔覆层内气孔形态,研究了熔覆层内气孔气体类型、分布规律以及影响因素.结果表明,熔覆层内气孔气体为CO,由石墨和氧或氧化物反应生成,气孔形状不规则、具有棱角状特征.气孔上浮形式并非垂直上浮,而是弥散式上浮.熔池内部强对流是影响气孔分布的内在因素.气孔运动幅度取决于熔池对流加速度,熔池温度越高,熔池表面张力梯度也越大,熔池对流的加速度越大.激光熔覆工艺是影响气孔分布的外在因素,适当降低激光功率和扫描速度、提高灰铸铁预热温度可有效消除熔覆层气孔缺陷,降低孔隙率.     

Heat treatment in high Cr white cast iron Nb alloy

Wear resistance of high Cr white cast irons can be improved by means of heat treatment. This type of cast iron alloy may present a microstructure with retained austenite. The amount of retained austenite changes with the applied heat treatment, which will have an influence on wear properties. The purpose of this work was to study the influence of several parameters such as quenching and tempering temperatures and subzero treatment in the wear performance of the high Cr white cast iron Nb alloy. In this way, the performance was evaluated using pin-on-disc abrasion test. The worn surface was examined by scanning electron microscopy, and the main wear mechanisms were identified. The microstructural characterization was also performed with carbide identification. This Fe alloy has proven to be good for applications in mining and alcohol-sugar industries.     

Microstructural features of magnesium cast iron poured into a block mold

Kharkov Automobile Road Institute. Bakinsk Factory of Oil Industry Machine Building. Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 1, pp. 54–56, January, 1990.     

铸铁等离子熔覆铁基合金耐磨涂层

利用等离子熔覆技术,选择合适的工艺参数,在硼铸铁基体上熔覆铁基合金粉末制备具有冶金结合的耐磨涂层.采用金相显微镜、X射线衍射仪、扫描电镜研究了涂层的组织,利用显微硬度计测试了涂层的显微硬度,通过环-块磨损试验评估了涂层的耐磨性.结果表明,硼铸铁等离子熔覆铁基合金涂层组织主要由(Cr,Fe)7C3,α-(Fe,Cr)和Fe3C相组成;涂层的显微硬度可达600～1 200 HV0.2;在干滑动磨损条件下,涂层的耐磨性约是基体试样的5倍.涂层中高硬度的(Cr,Fe)7C3及Fe3C相的抗磨骨架作用,大量Cr,Si原子溶入基体引起的过饱和固溶强化作用,涂层快速加热及快速凝固产生的细晶强化作用是涂层耐磨性提高的主要原因.     

高硅合金耐热铸铁生产球墨铸铁模具的研制

对铸铁模具使用工况进行了分析,采用了高硅合金耐热铸铁为生产球墨铸铁模具的材质,并介绍了高硅合金耐热球墨铸铁模具的消失模铸造工艺、冶炼工艺、热处理工艺以及该材质模具的实际使用效果。实际生产表明：高硅合金耐热球墨铸铁具有优越的综合耐热疲劳性能,大大提高了模具寿命。     

孕育量及合金加入量对缸体渗漏的影响

验证并论述了孕育量及合金加入量对缸体渗漏的影响，通过调整炉前处理工艺，严格控制孕育量及合金加入量，有效地防止了气缸体的试压渗漏现象。