弯曲试验是评定焊接接头焊接质量的常用手段,但对于如何选择恰当的弯曲直径,不同标准存在较大差异.文中首先推导了焊接接头弯曲伸长率计算理论公式,并对焊接接头进行了有限元分析,验证了理论公式的正确性;进一步根据分析结果对理论公式进行了修正,分别得出了两种弯曲方法下最小弯曲直径的计算公式;然后对不同规格焊接接头进行了实际的弯曲试验,验证了计算公式的正确性;最后将公式计算结果与中国船级社标准进行了对比,结果表明,船级社推荐的弯曲直径更接近三点弯曲时的计算结果,但当弯曲直径较小时,建议采用辊筒弯曲方法.

Polynitrostyrene was synthesized with fuming nitric acid by one-step method. The influences of polymerization temperature, polarity of solvent, reaction time and addition of sulfuric acid on the polymerization-nitration were studied. The results show that the relative molecular mass of the resultant product rises and the yield is improved with the decrease of the polymerization temperature and the increase in the polarity of solvent, reaction time and the mass percentage of sulfuric acid in the mixed acid of fuming nitric acid and sulfuric acid. The degree of nitrato-substitution reduces with the decrease of the polymerization temperature, while it increases when reaction time is extended and the amount of sulfuric acid rises.

<正>(专利申请号:201010167495.9,专利公开号:CN101823188A)1技术领域此发明属于钎焊材料技术领域。涉及一种钎焊Si3N4陶瓷的高温非晶钎料,更具体地说是涉及一种Ti-Zr-Cu-B高温活性非晶钎料。2背景技术Si3N4陶瓷是一种很有前途的工程结构陶瓷材料,

The copper joints were brazed with CuP7.7Sn5.4Ni14Si0.2Zr0.04 amorphous filler metal and conventional filler metal.The microstructures of filler metal and brazing joints were analyzed and the effect of brazing procedures on joints strength was studied.The results indicate that brazing procedures affect the strength of the brazing joints with both the CuP7.7Sn5.4Ni14Si0.2Zr0.04 amorphous filler metal and conventional filler metal.Compared to the amorphous brazing filler metal,conventional filler metal was more sensitive to the brazing procedure.In the same experimental conditions,shear strength of the joint brazed with amorphous brazing filler metal increased by 30% or more compared to the joint which brazed with conventional filler metal.CuP7.7Sn5.4Ni14Si0.2Zr0.04 amorphous brazing filler metal has no obvious phase structures in microscope,while the microstructure of conventional filler metal is mainly composed of primary(Cu,Ni)3P and(α-Cu+Cu3P) eutectic and(α-Cu+Cu3P+δ) ternary eutectic.The microstructure of diffusion and interface zone in joint brazed with CuP7.7Sn5.4Ni14Si0.2Zr0.04 amorphous brazing filler metal are mainly composed of α-Cu solid solution,and the center in the brazing seam is mainly composed of α-Cu and(Cu,Ni)3P and(α-Cu+Cu3P) eutectic and(α-Cu+Cu3P+δ) ternary eutectic.

采用CuP7．7Sn5．4Nil4Si0．2Zr0．04晶态与非晶钎料钎焊紫铜，通过微观手段对比分析了钎焊温度和保温时间对晶态与非晶态钎料钎焊接头成分和组织的影响．结果表明，CuP7．7Sn5．4Nil4Si0．2Zr0．04非晶钎料钎焊接头由界面区、扩散区以及钎缝中心区组成；随钎焊温度提高或保温时间增加，晶态钎料和非晶钎料钎焊接头界面区和扩散区不断增大，母材热影响区和钎缝中心组织也不断粗化，过高的钎焊温度或过长的保温时间，均会使界面区出现脆性相，但非晶钎料这种影响要小得多；在相同条件下，非晶钎料和母材的相互作用明显比相应的晶态钎料剧烈，其钎缝界面区较为均匀、连续，钎缝中心组织要明显均匀、细小．