Corrosion properties of high silicon iron-based alloys in nitric acid

The effect of copper and rare-earth elements on corrosion behavior of high silicon iron-based alloys in nitric acid was studied by means of static and loading current corrosion experiments.The anodic polarization curve was also made to discuss the corrosion mechanism.The examination on alloy microstructure and SEM corrosion pattern showed that when silicon content reached 14.5%,the Fe3Si phase appeared and the primary structure of the iron-base alloy was ferrite.When adding 4.57% copper in the iron alloy,its corrosion resistance in static diluted sulfuric acid was improved while its corrosion resistance and electrochemical corrosion properties in the nitric acid were decreased.In contrast,the addition of rare earth elements could improve the corrosion properties in all above conditions including in static diluted sulfuric acid and in nitric acid.

建筑用不锈钢减振复合板冷却工艺制度研究及C弯板形优化

使用酒钢自产的0.26 mm 304不锈钢和0.9 mm镀锌板,利用引进新型复合材料生产线开发1.2 mm不锈钢减振复合板,研究了10种冷却方式对C弯板形的影响规律。研究结果表明:在镀锌板加热温度为260℃、不锈钢板加热温度为125℃,产线速度6 m/min的条件下,最佳的冷却工艺为全开1、2、3区上层水且关闭1、2、3区下层水;通过降低基板的冷却强度和提高复板的冷却强度可有效改善C弯;上层冷却强度越大,下层的冷却强度越小,形成的C弯越小;上层1区水开关对不锈钢减振复合板板形C弯的影响最大。

减振复合板阻尼测试样品模态分析及尺寸确定

针对减振复合板样品在阻尼测试中样品尺寸标准不一,样品尺寸在确定时缺乏理论依据,无法确定测试样品尺寸的问题,利用有限元方法对减振复合板进行模态分析,用悬臂梁法进行阻尼实测。有限元模拟结果表明,在一定的宽度和厚度下,随着试样长度的增加,其1阶到6阶共振频率均出现降低的规律;在一定的长度和厚度下,随着样品宽度的增加,前4阶共振频率有略微增加的趋势;在一定的长度和宽度下,随着样品厚度的增加,1阶到3阶的共振频率基本保持稳定。实测结果表明,选取自由端长度为216mm、宽度为12.7mm的样品,利用2阶和3阶共振频率下的损耗因子进行阻尼表征较为合理。