简易炉外处理在电炉钢生产中的应用

阐述了小电炉采用投资少，见较快，简单易行的炉外处理措施，提高了钢质量和生产率，生产实践和应用结果表明，本措施可为同类型企业的炼钢工艺完善和技术进步提供参考。     

THE FRACTURE MECHANISM OF 475°C EMBRITTLEMENT IN A DUPLEX STAINLESS STEEL

The mechanism of “475°C embrittlement” of a duplex stainless steel was investigated using finite element modelling of the stress distribution at brittle fracture initiation. Brittle fracture initiated at a critical shear stress, which increased with ferrite hardness. The fracture stress was affected by the duplex microstructure. Fracture was nucleated by deformation twins, which were identified using electron back-scatter diffraction. The ductile-to-brittle fracture transition was sensitive to age-hardening and could be described simply by the effect of age-hardening and test temperature on the yield stress.     

低合金高强度钢的微观组织和疲劳裂纹扩展行为

用透射电镜观察了３０ＣｒＭｎＳｉＮｉ２Ａ钢等温的微观组织，疲劳裂纹扩展行为、裂纹尖端塑性区和位错结构，结果表明，等温状态组织由马氏体和贝氏体组成。在一个奥氏体晶粒内一般存在四个板条领域、裂纹尖端的塑性区内存在主位错带，疲劳断裂的基本组织单元为板条晶或板条束。裂纹遇到板条束界时方向发生较大偏斜。     

Failure analysis of a wire rope

Wire ropes, pulleys, counterweights, and connecting systems are used for auto tensioning of contact wires of electric railways. A wire rope in one such auto tensioning system suffered premature failure. Failure investigation revealed fatigue cracks initiating at nonmetallic inclusions near the surface of individual wire strands in the rope. The inclusions were identified as Al-Ca-Ti silicates in a large number of stringers, and some oxide and nitride inclusions were also found. The wire used in the rope did not conform to the composition specified for AISI 316 grade steel, nor did it satisfy the minimum tensile strength requirements. Failure of the wire rope was found to be due to fatigue; however, the ultimate fracture of the rope was the result of overload that occurred after fatigue failure had reduced the number of wire strands supporting the load.     

广州中城广场主体工程施工技术

广州中城广场工程结构形式复杂，平面曲折多角。施工中在应用多种模板体系、泵送混凝土、无粘结预应力楼板及核心筒部分小平台滑模等方面，采用了多项新技术，保证了工程质量，加快了工程进度。     

Pullout tests of epoxy-coated reinforcement in concrete

The bond strength and slip of epoxy-coated reinforcing bars in concrete have been evaluated by carrying out single pullout and double pullout tests. In extended single pullout tests, slip measurements were made while tensile force was applied to reinforcing bars embedded in concrete. In double pullout tests, 20 cycles of load were applied at levels of steel stress between zero and 0·5 times characteristic steel strength. Strains were measured by electrical resistance strain gauges glued inside the bars. Both epoxy-coated and uncoated bars were used in the investigation, to obtain comparative results. The strain gradient along the bar was found to be less for the coated reinforcement. In general, the epoxy coating was found to increase slip in bond and thereby reduce the bond performance of coated bars.     

连铸铝镇静钢的钢水准备

在连铸生产铝镇静钢时,水口絮流一直是困扰工程技术人员的一个难题.从絮流的原因入手,分析了Al2O3生成的控制.并介绍了几种钢水钙化的方法,从中比较出用复合造渣材料来解决浇铸铝镇静钢的优点.     

焊接波浪状边缘薄钢带的高上山成型法

介绍了高上山成型法的工艺特点及理论上的可行性和实践中的可靠性，此方法能有效地解决薄钢带波浪状边缘的焊接方面存在的问题。     

几种高强度钢腐蚀疲劳裂纹扩展行为的研究

本文研究了ＧＣ－４，３０ＣｒＭｎＳｉＮｉ２Ａ和３００Ｍ超高强钢的腐蚀疲劳裂纹扩展行为。考虑了环境，热处理制度，应力比和频率对裂纹扩展的影响。研究结果表明：腐蚀环境和热处理制度对疲劳裂纹扩展有显著影响。在侵蚀性环境中随频率降低，裂纹扩展大幅度上升，随应力比提高，环境影响加剧。利用扫描电镜对试样断口形貌进行了分析，并讨论了高强钢的腐蚀疲劳机理。     

Ti,N,Mg对M2高速钢凝固组织和硬度的影响

为了改善Ｍ２高速钢共晶碳化物的分布，本文利用小凝固试样变质的方法研究了Ｔｉ，Ｎ和Ｍｇ对Ｍ２高速钢凝固组织和硬度的影响。试验结果表明，加入Ｔｉ或Ｔｉ－Ｎ后，共晶碳化物形态和分布有很大改善，而加入Ｔｉ－Ｎ后对凝固组织有轻微的细化作用，但只添加Ｔｉ不补碳时，钢的淬火硬度和回火硬度均下降；加入适量的Ｍｇ可以使片状的Ｍ２Ｃ型共晶碳化物转为鱼骨状的Ｍ６Ｃ型共晶碳化物，使其分布有所改善，Ｔｉ和Ｍｇ复合加入可以明