Influence of Billet Size on Flow, Solidification and Solute Transport in Continuous Casting

ListofSymbol　　B———Buoyancy ,m·s- 2 ;　　c———Concentrationofsoluteelement ;　　Cμ———Turbulentconstant;　　D———Diffusivityofsoluteelement ,m2 ·s- 1 ;　　fl,fs———Liquidandsolidfraction ;　　fμ———Turbulentcoefficient ;　　h———Enthalpy ,J·kg- 1 ;　　k———Turbulentkineticenergy ,m2 ·s- 2 ;　　kp———Equilibriumpartitioncoefficient;　　Kp———Permeabilityofmushyzone ,m2 ;　　K0 ———Permeabilitycoefficient;　　p———Pressure ,Pa ;　　Pr———Prandtlnumber ;…     

Improvement in Stress Corrosion Crack Growth Resistance of an Austempered Cast Steel by a Novel Two-Step Austempering Process

An investigation was carried out to examine the influence of microstructure on the stress corrosion cracking (SCC) growth behavior of an austempered high-carbon (1.00%), high-silicon (3.00%), and high-manganese (2.00%) cast steel. Compact tension specimens were prepared from this cast steel as per American Society for Testing Materials standard E-399 and were given four different heat treatments to produce different microstructures. The SCC behavior of these specimens was studied in 3.5% NaCl solution. The test results indicate the K_ISCCvalue of the material increases as the austenite content increases. Significant improvement in SCC resistance was achieved by using a novel two-step austempering process. Intergranular crack growth was observed in all these specimens.     

乙烯装置失效模式分析及基于风险的检验

简述了乙烯装置的工艺流程,分析了装置中常见的几种失效模式及其分布;以乙烯裂解装置为例,简述了RBI的执行过程和结果,从基于风险的检验理念,对制订设备检验策略提出了几点建议。     

乙烯裂解炉辐射炉管施工技术

乙烯裂解炉辐射炉管的施工比较复杂,文章结合吉林石化分公司15万t／a乙烯装置节能改造项目的施工实践,介绍了辐射盘管系统施工的准备工作、辐射盘管组装顺序、集管箱开孔及组焊、猪尾管预制安装、辐射盘管吊装等方面的施工经验。     

建(构)筑物机械拆除方法综述

介绍了几种常用的建(构)筑物机械拆除方法,对其工作原理、特点、应用条件及局限性加以分析和说明。     

穿壁焊极柱合金探索

本文对起动用铅酸蓄电池穿壁焊极柱用合金配方进行了探索 ,并得到了良好的应用效果     

Structure of rapidly solidified aluminum alloys

This paper is a summary of an extensive research program carried out by the authors on the structure of rapidly solidified aluminum alloys; and a comparison with the work of others also involved in this field. The paper discusses the changes in the dendritic and non-dendritic structure of the matrix at cooling rates from 10^–3 to 10¹⁰ K/s and discusses the hetergeneity of the structure caused by interdendritic-segretion during solidification.     

定向凝固Al/C复合材料研究

本文首次进行了Al/C(SiC)复合材料定向凝固,研究了复合材料定向凝固过程以及组织形态与凝固速率的关系,获得了纤维束间胞晶和不同间距的树枝晶,发现非润湿系统复合材料定向凝固后性能降低,文中对其机制进行了探讨.     

催化裂化干气回收乙烯用于制备环氧乙烷的研究

叙述了在YS型银催化剂作用下，利用催化裂化干气回收的乙烯制备环氧乙烷的实验研究。结果表明：在银催化剂上催化氧化生成环氧乙烷的过程中，使用回收的乙烯，催化剂的初选择性可达80％；在保持环氧乙烷时空产率不变，经过2000h催化剂稳定性试验后，选择性下降了3—4个百分点，反应温度上升约10℃，与用聚合级乙烯为原料进行比较，催化剂初选择性低2—3个百分点、稳定性略差。该结果为用回收乙烯生产环氧乙烷提供了试验依据。     

高能超声处理对锡锑包晶合金凝固组织的影响

在锡锑包晶合金的凝固过程中导入高能超声，不仅显著细化α相和β相晶粒组织，同时使具有立方晶体特征的β相组织有明显的球化趋势，消除了密度偏析，分析了高能超声细化凝固组织的机理。