Ti230合金电阻点焊接头组织与显微硬度研究

对0.7 mm厚的Ti230合金板电阻点焊接头的组织及显微硬度进行了研究。结果表明:Ti230板材焊接过程中易发生结合线伸入,并且结合线伸入附近同时存在裂纹,结合线伸入产生的原因是焊接参数选择不合理。通过改变试验参数,即增加压力,减小热量输出可以明显改善结合线伸入现象;Ti230合金的组织为等轴状α基体+金属间化合物Ti2Cu粒子,焊缝处组织为铸态组织,Cu元素完全固溶到基体;焊缝处的显微硬度明显高于基体的显微硬度,可能是由于焊接后未进行热处理,存在较大焊接应力,且Cu元素在基体中较高的固溶度。

丁二烯球罐进出口位置设计要点

丁二烯具有致癌性,属于极度危害介质,目前大量存储在球形储罐中,但是丁二烯进出口设置在球罐下极与标准要求不符,通过工程实例对丁二烯球罐进出口位置的设计要点进行了探讨,不仅总结提出了进出口设置在上极的缺陷和不足而且对丁二烯球罐进出口下极开孔的方案提出了比较有效的防护措施,对以后丁二烯球罐进出口位置设计提供了很好的借鉴。

Joule-Thomson Expansion of d-Dimensional Charged Anti-de Sitter Black Holes Surrounded by Quintessence with a Cloud of Strings Background

Effects of the dimension on the Joule-Thomson expansion are investigated in details by considering the case of d-dimensional(d≥5)charged anti-de Sitter(AdS)black hole which is surrounded by the quintessence with a cloud of strings background.Firstly,the thermodynamic quantity of this black hole is reviewed.Secondly,three important features of the Joule-Thomson expansion in different dimensions are discussed,including the Joule-Thomson coefficients,inversion curves,and isenthalpic curves.Finally,the effects of the charge,the quintessence and strings cloud parameters on the Joule-Thomson expansion in the case of six-dimensional black hole are studied.