新型穿孔顶头的研制

研制了Φ５０ｍｍ穿孔机用新型小规格穿孔顶头。介绍了该穿孔顶头的材料选择原则及外形曲线和内孔结构设计原理、制造工艺、热处理工艺和使用时的冷却状况等。实践表明,该新型穿孔顶头使用寿命较长,使用效果良好。     

高寿命顶头的研制

介绍了高寿命无缝钢管穿孔顶头加工的工艺原则、典型穿孔顶头的结构设计和热处理工艺制度以及使用效果。     

两辊穿孔顶头的热处理工艺

介绍了在无缝钢管生产中,两辊穿孔顶头的热处理方法。根据两辊顶头的主要失效形式对顶头的工作状态及热处理工艺作了分析,通过热处理试验,对两辊穿孔顶头选择了最优热处理方案,得出了两辊穿孔顶头的最重要热处理的目的是获得表面良好的高温润滑性能以及两辊穿孔顶头最适宜于采用内外水冷的结论。该工艺在实际生产中取得了良好的效果,两辊顶头质量一直较稳定。     

精密热模锻穿孔顶头生产工艺

本文介绍了精密热模锻穿孔顶头的生产工艺及工艺特点。采用这种工艺生产顶头,金属消耗系数低,使用寿命高于铸造、锻造顶头。     

镶嵌式钼合金穿孔顶头的研制

介绍了镶嵌式钼合金穿孔顶头的研制过程。具体分析了穿孔顶头的使用工作条件和失效形式,对穿孔顶头改进的方案设计、材料选择、结构形式和加工工艺以及使用效果进行了具体的介绍。镶嵌式钼合金穿孔顶头尤其适用于低合金钢及合金高压锅炉管的穿孔。     

涂层组合材料穿孔顶头

应用真空熔结涂层工艺研制出涂层组合材料穿孔顶头。介绍了该顶头的涂层材料、性能特征和研制工艺以及使用效果。     

二辊斜轧穿孔顶头的改进

根据轧辊和轧件在辗轧区内存在的共轭几何关系提出新的二辊斜轧穿孔顶头设计方法及其推导计算式。介绍了顶头工作段和反锥段设计原则以及设计实例。工业性试验结果表明，新设计的穿孔顶头能显著提高毛管的横向壁厚精度。     

钢管斜连轧工艺参数对轧制力及荒管尺寸精度的影响

为分析斜连轧工艺参数对轧制力及荒管尺寸精度的影响,取工艺变参数及范围:顶头前伸量15~28 mm、穿孔段送进角7°~9°、穿孔段孔喉34~35 mm、轧管段轧辊转速182~190 r·min-1,在斜连轧实验机组上对Φ40、Φ42 mm的管坯进行单变量多组实验。结果表明:在实验参数范围内,随顶头前伸量增大,穿孔段轧制力减小,顶头轴向力先减小后增大;随送进角的增大,穿孔段轧制力减小,顶头轴向力微增大;当管坯直径一定时,随孔喉减小,轧制力增大,而当孔喉一定时,随管坯直径增大,轧制力增大。在穿孔段工艺参数一定时,轧管段轧辊速度不同的情况下,若张力轧制时穿孔段及轧管段轧制力均减小,相反若推力轧制时均增大。对斜连轧后荒管的分析结果显示微张力轧制得到的荒管壁厚精度达±0.2 mm,外径精度达±0.35 mm。     

新型穿孔顶头的研究

介绍了穿孔顶头的工作条件和主要失效形式，以及新型穿孔顶头的设计。确定了顶头的生产工艺。使用结果表明，新型穿孔顶头在穿孔中能保持良好的流线型外形，产生光滑的再生氧化层，防止塌鼻失效，提高了使用寿命。     

苏联对穿孔顶头的研究与应用

本文概略地介绍了苏联列宁钢管厂等厂家近十几年来对穿孔顶头材质、生产方法和提高顶头使用寿命措施等方面的研究成果,较详细地介绍了穿孔顶头精密热模锻工艺。目前我国在穿孔顶头的生产、使用及研制方面都与苏联有很大差距。本文所介绍的经验很值得借鉴。     

铝与钢异种金属焊接的研究与发展概况

分析了铝与钢的焊接性,综述了国内外铝与钢异种金属焊接的研究与发展状况,重点介绍了目前应用于铝与钢连接的焊接方法,并对各种焊接方法的优缺点作了分析比较.     

先进陶瓷的现状及进展

简要综述了先进陶瓷的现状与进展。介绍了目前先进陶瓷的主要材料、应用及市场情况,同时表述了先进陶瓷目前的形势、面临的问题及发展趋势。     

MICROSTRUCTURE AND MECHANICAL BEHAVIOUR OF Al-Li-Zr AND Al-Li-Cu-Mg-Zr ALLOYS

The aging response,tensile and impact properties of two kinds of Al-Li based alloys havebeen studied.The microstructure,deformation as well as fracture behaviour in the alloys wereobserved with SEM and TEM.It was found that the mechanisms of deformation and fracturefor different heat-treated alloys with the same chemical composition are quite different.Thecauses leading to the drop of ductility,toughness as well as anisotropy in peak-aged alloyshave been analysed.Finally,possible methods to improve the ductility and toughness of the al-loys have been discussed.     

Al-Li-Zr和Al-Li-Cu-Mg-Zr合金的显微组织和力学性能

研究了两种Al-Li基合金的时效硬化、拉伸和冲击等力学行为,用透射电镜和扫描电镜对合金的显微组织结构,变形和断裂的特征进行了分析。结果指出:同一成分、不同热处理态的合金变形和断裂的机制截然不同。分析了时效态合金韧性下降和产生冲击各向异性的原因。讨论了改善Al-Li合金塑、韧性的可能途径。     

INFLUENCE OF COLD-WORKING AND HEAT TREATING ON ELASTIC PROPERTIES OF Nb AND Nb-BASE ALLOYS

The elastic limit of single-phase alloy Nb-2Mo-2Zr-1Ti is higher as recovered state incomparison with as cold-rolled or recrystallized one.For Nb-40Ti-5.5AI alloy ofage-hardening type,the elastic limit is lower as cold-rolled state,but increases considerablyafter proper aging.However,its elastic modulus changes no more,so the stored-energy(σ_e~2/E)may raise significantly.The temperature dependence on elastic modulus for pureNb as intensely cold-worked or recrystallized state is anomalous.This anomaly may disap-pear after recovered treatment of intensely cold-worked state at 600℃ for 4 h.and maychange no more after that of recrystallized state.The anomalous behaviour of elasticity wasalso discussed on the non-magnetic Nb.     

Bi在Fe液中的溶解平衡及Ni,Mn的影响

用气液平衡法,在密封Mo反应室中研究了1873K下Fe液中Bi蒸气溶解平衡及第三组元Ni,Mn对其的影响,测定了1873K下Bi在Fe液中的溶解量(wt—%)为0.16。Ni,Mn增加Bi的溶解量,其活度相互作用系数为e_(Bi)~(Ni)=-0.20,e_(Bi)~(Mn)=-0.19。     

EFFECT OF CARBON CONTENT ON MICROSTRUCTURE AND PROPERTIES OF HIGH STRENGTH AND HIGH ELONGATION STEELS

The micro structure and mechanical properties of new kind of hot-rolled high strength and high elongation steels with retained austenite were studied by discussing the influence of different carbon content. The research results indicate that carbon content has a significant effect on retaining austenite and consequently resulting in high elongation. Besides, new findings about relationship between carbon content and retained austenite as well as properties were discussed in the paper.     

EFFECTS OF AGING TEMPERATURE AND TIME ON MICROSTRUCTURE AND MECHANICAL PROPERTIES OF AN Fe-BASE SUPERALLOY

The mechanical properties and microstructure of an Fe-base superalloy GH35A have been examined after aging at 650—750℃ for 100—10000 h.The tensile strength of the alloy changes no more with aging temperature and the time at room temperature,but the ductility and impact toughness at room temperature,as well as the stress-rupture life up to 700℃ de- crease slowly during aging up to 10000 h The initiation time to worsen its properties becomes shorter as the aging temperature rises.The variation of the mechanical properties of the alloy was found mainly depending on the formation,morphology,distribution and characteristic of the σ-phase precipitation.     

MORPHOLOGY AND PHASE TRANSFORMATION OF GRANULAR BAINITE AND GRANULAR STRUCTURE

本文研究了低碳合金钢奥氏体在连续冷却或等温转变过程中形成的组织形态和转变机理。结果表明在中温贝氏体区得到“粒状贝氏体”组织,在先共析转变区得到“粒状组织”。两者都有“铁素体基体+小岛”形貌。但前者有表面浮凸现象,铁素体呈长条状,与母相维持K-S关系,惯习面为{111}_γ,小岛也多星长条状平行排列。后者无表面浮凸,铁素体呈无规则形状,与母相无严格位向关系,小岛亦呈无规则排列。然而这两种组织都是由扩散型相变机制形成的。最后,提出了形成这两种组织的相变模型。     

MODELLING OF MICROSTRUCTURE EVOLUTION AND PROPERTIES OF LOW-CARBON STEELS

1.IntroductionMicrostructureprocessmodelsareincreasinglyonhotstriprollingofste.l[1--7].Thesemodelsfrequentlyincorporateagreatdealofempiricismwithcomparativelytightprocessrangesofapplicability.Morefundamentallybasedprocessmodelsarerequiredtodeveloppredictivetoolstooptimizetheproductionforawiderangeofmilldesignsandprocessingconditions.Theprocessofhotstriprollingoflow--carbonsteelscanbesubdividedintothreeprin-cipalstages:(i)reheating,(n)rollingand(iii)cooling(watercoolingontherun--outtableandsubs…