Ballpoint pen tip steel, a super free-cutting stainless steel, exhibits excellent corrosion resistance and good machining properties. In this study, inductively coupled plasma spectroscopy, metallographic microscopy, ...Ballpoint pen tip steel, a super free-cutting stainless steel, exhibits excellent corrosion resistance and good machining properties. In this study, inductively coupled plasma spectroscopy, metallographic microscopy, and scanning electron microscopy were used to determine the elemental contents in five ballpoint pen tips and their components, morphologies, and inclusion distributions. The results showed that the steels were all S–Pb–Te super free-cutting ferritic stainless steel. The free-cutting phases in the steels were mainly Mn S, Pb, and small amounts of Pb Te. Mn S inclusions were in the form of chain distributions, and the aspect ratio of each size inclusion in the chain was small. The stress concentration effect could substantially reduce the cutting force when the material was machined. Some of the Pb was distributed evenly in the steel matrix as fine particles（1–2 μm）, and the rest of the Pb was distributed at the middle or at both ends of the Mn S inclusions. The Pb plays a role in lubrication and melting embrittlement, which substantially increases the cutting performance. Pb Te was also usually distributed in the middle and at both ends of the Mn S inclusions, and Te could convert the sulfides into spindles, thereby improving the cutting performance of the steel.展开更多
利用高效液相色谱法对圆珠笔油墨中含有的结晶紫、甲基紫和碱性品蓝3种三苯甲烷类染料进行检测,流速为0.8 min/L,流动相是乙腈与NH4HCO3溶液(p H 8.0)混合后的缓冲液(体积比为60∶40),检测波长580 nm,在此条件下3种染料能达到很好的分...利用高效液相色谱法对圆珠笔油墨中含有的结晶紫、甲基紫和碱性品蓝3种三苯甲烷类染料进行检测,流速为0.8 min/L,流动相是乙腈与NH4HCO3溶液(p H 8.0)混合后的缓冲液(体积比为60∶40),检测波长580 nm,在此条件下3种染料能达到很好的分离。分别考察了圆珠笔字迹在红外光照射、日光照射、紫外光照射、烘箱加热以及避光放置等老化环境下,3种三苯甲烷类染料随时间的变化情况。利用检测结果绘制了归一化曲线和三相图。结果表明:三苯甲烷类染料受日光和红外光照射后,发生的变化明显大于紫外灯、烘箱加热和避光保存的老化条件。此结果可为鉴别较长时间的圆珠笔油墨书写时间提供依据。展开更多
基金supported by the National Nature Science Foundation of China (No. 51474142)
文摘Ballpoint pen tip steel, a super free-cutting stainless steel, exhibits excellent corrosion resistance and good machining properties. In this study, inductively coupled plasma spectroscopy, metallographic microscopy, and scanning electron microscopy were used to determine the elemental contents in five ballpoint pen tips and their components, morphologies, and inclusion distributions. The results showed that the steels were all S–Pb–Te super free-cutting ferritic stainless steel. The free-cutting phases in the steels were mainly Mn S, Pb, and small amounts of Pb Te. Mn S inclusions were in the form of chain distributions, and the aspect ratio of each size inclusion in the chain was small. The stress concentration effect could substantially reduce the cutting force when the material was machined. Some of the Pb was distributed evenly in the steel matrix as fine particles（1–2 μm）, and the rest of the Pb was distributed at the middle or at both ends of the Mn S inclusions. The Pb plays a role in lubrication and melting embrittlement, which substantially increases the cutting performance. Pb Te was also usually distributed in the middle and at both ends of the Mn S inclusions, and Te could convert the sulfides into spindles, thereby improving the cutting performance of the steel.
基金Supported by the National Natural Science Foundation of China(21145006)Scientific Research Common Program of Beijing MunicipalCommission of Education(KM201110028009)
文摘利用高效液相色谱法对圆珠笔油墨中含有的结晶紫、甲基紫和碱性品蓝3种三苯甲烷类染料进行检测,流速为0.8 min/L,流动相是乙腈与NH4HCO3溶液(p H 8.0)混合后的缓冲液(体积比为60∶40),检测波长580 nm,在此条件下3种染料能达到很好的分离。分别考察了圆珠笔字迹在红外光照射、日光照射、紫外光照射、烘箱加热以及避光放置等老化环境下,3种三苯甲烷类染料随时间的变化情况。利用检测结果绘制了归一化曲线和三相图。结果表明:三苯甲烷类染料受日光和红外光照射后,发生的变化明显大于紫外灯、烘箱加热和避光保存的老化条件。此结果可为鉴别较长时间的圆珠笔油墨书写时间提供依据。
