利用热胀冷缩原理拆除炼钢转炉主动耳轴的方法

在组装炼钢转炉主动耳轴和耳轴块的过程中,由于组装方法不当导致主动耳轴装配不到位。为取出装配不到位的主动耳轴,通过对炼钢转炉主动耳轴装配结构的分析,得出利用主动耳轴块热胀与主动耳轴冷缩相结合的原理,在耳轴块内孔膨胀、主动耳轴冷缩的情况下,利用主动耳轴自重力的作用,拆除了装配不到位的主动耳轴,解决了主动耳轴装配不到位拆除主动耳轴的难题。此方法的成功应用,为产品的过盈装配和过盈拆除拓宽了思路和方法。

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.

玉米机械收获子粒破碎率与含水率关系的品种间差异

基于2012～2017年在北疆大田机械粒收条件下获取的收获质量评价数据,分析当地主栽的9个品种机械粒收过程中子粒破碎率和含水率的关系。调查范围内,不同品种收获期子粒含水率平均值分布范围为19.6%（KX9384,KWS1568）～28.2%（联创808）,破碎率平均值分布范围为2.8%（新引M753）～8.5%（KWS2564）,收获时品种间子粒含水率和破碎率均存在显著差异。分析显示,虽然131个样本子粒含水率（y）与破碎率（x）之间呈极显著正相关（r=0.302＊＊）,符合二次曲线（y=ax^2＋bx＋c）关系,但不同品种破碎率对子粒含水率的响应程度具有一定差异。在相同含水率条件下不同品种耐破碎性能存在较大差异,相应满足国标破碎率≤5%和≤8%要求适宜收获的子粒含水率范围也不同。筛选出新引M751、新引M753、KX9384、登海618和先玉335等耐破碎性能较好的品种。