冷却机机头大直径法兰的焊接工艺

通过对不锈钢大直径法兰焊接过程中出现的裂纹及变形进行分析,提出了防止焊缝裂纹及焊接变形的工艺措施。     

Q345E低合金高强度钢Φ600 mm连铸圆坯的生产实践

Q345E钢(/%:0.14~0.17C、0.20~0.30Si、1.28~1.38Mn、≤0.011P、≤0.005S、0.015~0.030Al、0.032~0.045V)大圆坯的生产流程为65 t LD-LF-VD-Φ600 mm圆坯CC工艺。通过出钢时滑板挡渣,加入预熔合成渣(/%:40~50CaO、≤9SiO₂、30~40Al₂O₃~7MgO、8~10Al)、钢芯铝、脱氧剂和合金,控制拉速0.22 m/min,32 t中间包钢水过热度(25±5)℃,恒液面900 mm,全程保护浇铸和电磁搅拌等措施,试生产法兰用Q345E钢Φ600mm连铸圆坯。生产结果表明,铸坯表面无可见冷疤、鼓肚等缺陷,中心缩孔0.5级,中心疏松1.0级,碳偏析≤1.09,-50℃低温冲击功超过100 J,完全满足标准要求。     

A rotary flange forming process on the lathe using a ball-shaped tool

Flanging of tube ends is carried out using casting or assembly joining, which have drawbacks due to improper strength, defect generation or low efficiency. In this work, flange forming of Al tubes was performed on the lathe utilizing a ball-shaped tool attached to the lathe carriage, and fed outwards radially while the specimen clamped to the lathe chuck and rotated. Tubular specimens, were rotated at 500 rpm, and the tool feed was 0.314 mm/rev. Ball diameter (D_ball) of 12.8 mm was fixed, while the tool advance distance (T_a) at the start of flanging was 0.125, 0.25, 0.5, 0.625D_ball. Oil was used as a lubricant. Results showed that the radial flanging force was increased as t₀ and T_a increased. An approximate contact area calculation was presented and the calculated loads were in agreement with the experimentally obtained ones. Relatively large flanging ratios (FR) were obtained and those were found to increase as t₀ decreases and T_a increases. Maximum thinning was observed at the flange edge followed by an increase in thickness towards the area between the tube and flange. Surface hardness increased as t₀ increased.     

垫片螺栓法兰连接系统的载荷与变形分析

分别在预紧和操作情况下 ,应用弹性理论对螺栓法兰系统进行了较为详细的载荷 变形分析 ,同时提出了将方程组的求解转化为优化问题 ,应用遗传算法结合牛顿迭代法来求解相关的非线性方程组。算例表明 ,考虑法兰旋转时更能反映螺栓法兰系统的真实受力情况。     

波导管与法兰盘电铸连接工艺的研究与应用

在波导管两端面上连接法兰盘时通常采取的是银钎焊工艺,由于银钎焊是一种高温连接从而带来了很多弊病：本文在充分论证试验后,实现了将波导管与法兰盘直接电铸成一体的新工艺技术。同时,本文还阐述了在实施该工艺过程中是如何较好地解决电铸模芯材料、连接强度、致密与韧性三大关键性技术。     

螺栓法兰连接的可视化设计

应用Visual Basic编程语言和Microsoft Access数据库管理系统实现了螺栓法兰连接的可视化设计。应用该软件可使传统的规范设计程序化和智能化，有效地提高了螺栓法兰连接设计的效率和质量。     

螺栓法兰连接系统的可靠性设计

总结了近年来螺栓法兰连接系统的理论分析和试验研究成果，避开了原有垫片系数“m、y”值，提出了可靠的设计方法，使其与工程实际更为接近。     

国内外钢结构设计规范的几点比较

以我国新修订的钢结构设计规范GB5 0 0 17 2 0 0 3为基础 ,结合美国钢结构设计规范LRFD 2 0 0 1及欧洲钢结构设计规范EC3,对 3本规范中拉、压杆的屈曲限值以及梁腹板受剪屈曲后强度的计算方法进行了计算分析和比较 ,有关分析结论可供工程技术人员了解国内外钢结构设计规范的技术水平和发展动态时参考     

Cyclic loading behavior of EBF links constructed of ASTM A992 steel

Cyclic loading tests were conducted to study the behavior of link beams in steel eccentrically braced frames. A total of thirty-seven link specimens were constructed from five different wide-flange sections, all of ASTM A992 steel, with link length varying from short shear yielding links to long flexure yielding links. The occurrence of web fracture in shear yielding link specimens led to further study on the cause of these fractures. Since the link web fracture appeared to be a phenomenon unique to modern rolled shapes, the potential role of material properties on these fractures is discussed. Based on the test data, a change in the flange slenderness limit is proposed. The link overstrength factor of 1.5, as assumed in the current U.S. code provisions, appears to be reasonable. The cyclic loading history used for testing was found to significantly affect link performance. Test observations also suggest new techniques for link stiffener design and detailing for link-to-column connections.     

小管径带颈法兰对接环焊缝的偏心角透照技术

本文论述了小管径钢管与带颈法兰对接环缝夜间的偏心角RT透照技术，采用手电筒直射模拟确定操作方位，RT演绎操作的原理，结合GB 3323标准的要求，有效的解决了夜间RT操作时确定偏移距离的不利影响，操作方便，有利于实际操作，也可对行业内小管径的探伤起到借鉴作用。