无碳化物贝氏体在曲轴上的应用与展望

介绍了无碳化物贝氏体钢的特点、合金化原理、获得方法和在曲轴上的应用前景。     

钢丝圈的失效分析

对72B纺织用钢丝圈进行失效分析，发现钢丝圈使用性能不合格的主要原因是热处理炉仪表指示温度偏差太大及热处理工艺规范不合理，使得球化退火后的金相组织出现粗晶铁素体，淬火和回火后的金相组织出现铁素体、粒状渗碳体，使材料塑性增加，满足不了使用性能。     

高温热冲击对J75合金力学性能影响及损伤机理

采用自行研制的大电流瞬态加热设备,研究了沉淀强化奥氏体不锈钢 J75 经受不同温度热冲击及在一定温度下经受多次热冲击作用后的力学性能变化规律,并探索了导致性能损伤的机理性原因。研究结果表明,在作用时间为 1 s 的情况下,温度低于 610 ℃,J75合金的力学性能无明显损伤,温度大于 750 ℃,材料的强度和延伸率都显著降低;温度在 610 ℃,增加有限次数的热冲击,对材料的强度和延伸率影响不很明显,但温度在 750 ℃时,随热冲击次数的增加,材料的强度和延伸率都明显降低。显微分析表明,热冲击温度和热冲击次数的增加,促进了合金晶粒细化,但使材料析出相发生了明显的变化,在高于 750 ℃下产生的大量片状 η 相的析出及 γ′强化相的粗化和不均匀分布,是引起 J75 合金强度和延伸率显著下降的主要原因。     

中国先进研究堆冷中子导管的模拟研究

应用蒙特卡罗方法对中国先进研究堆(CARR)上的两条冷中子导管CNG1和CNG2的设计方案进行了模拟研究。在假定的冷中子源谱分布下,两条导管出口处的中子注量率均达到1×109cm-2·s-1以上。CNG1和CNG2的中子传输效率分别为50%和42%,中子束最大发散角分别为2 2°和1 9°。中子束沿水平方向的分布均匀,其最大起伏不超过3%。重力显著影响中子束沿垂直方向的分布。     

Aspects of microstructure in low carbon steels produced by the CSP process

The solidification structure, microstructure evolution during rolling and precipitates with nanometers in dimension of the low carbon steels produced by CSP process with thin slabs have been studied in recent years. Important differences in microstructure and mechanical properties between the CSP products and the conventional one were observed. These differences may arise from the much rapider solidification rate and cooling rate after casting of the thin slabs. Some aspects of the microstructure for the low carbon steels of the CSP thin slabs are summarized and compared with the conventional one.     

Development of grain boundary allotriomorphic ferrite/granular bainite duplex steel

A new hot-rolled low alloy high strength steel with grain boundary allotriomorphic ferrite/granular bainite duplex micro-structure has been developed through novel microstructure and alloying designs without any noble metal elements such as nickel and molybdenum. Its as-rolled microstructure and mechanical properties, fatigue crack propagation behavior compared with single granular bainitic steel as well as continuous cooling transformation, were investigated in detail. The measured result of CCT (continuous cooling transformation) curve shows that such duplex microstructure can be easily obtained within a wide air-cooling rate range. More importantly, this duplex microstructure has much better combination of toughness and strength than the single granular bainite microstructure. It is found that the grain boundary allotriomorphic ferrite in this duplex microstructure can blunt the rni-crocrack tip, cause fatigue crack propagation route branching and curving, and thus it increases the resistance to fati     

双束强辐照对氧化物弥散强化铁素体型合金强化相稳定性影响

采用双束复合辐照装置,研究了He存在条件下,强辐照对长期时效后的ODS合金中强化相(Y2O3)的稳定性和辐照损伤特征的影响。实验结果表明:双束强辐照下,ODS合金中强化相不稳定,发生聚集长大并造成附近基体中Ti、Y浓度增高,导致空洞尺寸和空洞肿胀增加,并对这一结果从理论上进行解释。     

130t/h高温高压循环流化床锅炉调试运行

对 130t h高温高压循环流化床锅炉的调试、运行及试验研究进行了全面的分析总结。重点介绍了冷态试验、热态试验、设备改造情况和运行分析总结     

Extrapolation Model of High Temperature Creep for 12Cr1MoV Steel

The creep curves of heat resistant steel 12Cr1MoV was investigated. by constant stress creep tests. The creep curves of constant stress creep are quite different from that of constant load creep. The original θ- Concept Project procedure can be validated to successfully describe the constant stress creep curves but not constant load creep. A modified θprocedure was developed. This approach can successfully described both constant stress creep and constant load creep curves. The new approach leads to a great improvement in accuracy of long term prediction of extrapolation due to validation of a great number of existing constant load creep data.     

火力发电厂工业冷却水系统工艺分析

从技术、经济和安全三个方面分析了采用不锈钢管材凝汽器的火力发电厂的工业冷却水系统，采用闭式循环工艺运行方式的合理性。