130t RH脱碳模型建立及超低碳钢处理工艺优化

建立了RH真空处理脱碳数学模型，并通过130t RH工业试验结果对此数学模型加以验证。根据模型分析了[C]0、[O]0、真空度、提升气体流量等对脱碳效果的影响，据此优化了处理工艺，取得较好的效果。     

NHD脱碳工段技改总结

合成氨装置脱碳工段采用NHD脱碳工艺,由于脱碳后的脱碳气中CO2含量偏高,造成H 2损耗较大,为此采用ZUPAC系列双向金属折峰式波纹填料和新型槽盘式液体分布器对脱碳塔进行改造。改造后,脱碳气中CO2体积分数从2.0%降至1.6%,年可增加经济效益1000万元左右。     

合成氨装置中高温氢腐蚀问题探讨

探讨合成氨装置中的高温氢腐蚀问题,结合实际说明高温氢腐蚀的影响因素,提出预防高温氢腐蚀的措施.     

Decarburization rate of RH refining for ultra low carbon steel

The decarburization behaviors of ultra low carbon steel in a 210-t RH vacuum degasser were investigated under practical operating conditions.According to the apparent decarburization rate constant (KC) calculated by the carbon content in the samples taken from the hot melt in a ladle at an interval of 1-2 min,it is observed that the total decarburization reaction period in RH can be divided into the quick decarburization period and the stagnant decarburization period,which is quite different from the tradit...     

Microstructure of a nitrided steel previously decarburized

In this study the effects of a surface-controlled decarburization on the structure of a nitrided steel are analyzed. Samples of a quenched and tempered 42CrMo4 steel were decarburized by heating in air at different depths and submitted to gaseous nitriding. After decarburization and nitriding, the microstructure of surface layers was investigated by optical microscopy (OM) and scanning electron microscopy (SEM). The nitrogen and carbon profiles in the diffusion layers were determined by SEM equipped with a wavelength dispersive spectrometer (EPMA-WDS) and by glow discharge optical spectrometry (GDOS). The effect of nitriding was determined by microhardness measurements. Our results indicate that a previous decarburization only slightly affects the surface hardness, but reduces the conventional nitriding depth. The decarburization also favors the nitrogen take-up and produces increased nitrogen concentrations in the compound layer and in the narrow zone beneath it.     

70t电炉脱碳方法的优化与分析

增大供氧强度，增加铁水热装比是缩短冶炼周期，减少电耗、铁损的有效途径。介绍了70t直流电炉在供氧流量增加后，增加铁水热装比快速脱[C]的实践。     

冷拉退火轴承钢退火后易出现的缺陷及挽救方法

通过控制温度及冷却度使冷拔材轴承钢退火后,得到珠光体球化组织提高工件的性能指标,便于后续加工同时对退火后出现的不良组织及超标准脱碳采取的挽救措施以提高生产效率。     

Decarburization Thermodynamics of High-Carbon Ferromanganese Powders During Gas-Solid Fluidization Process

 Thermodynamic conditions of reactions between high-carbon ferromanganese powders and gas decarbonizers like O2, CO2 and water vapor were studied by thermodynamic calculation. In O2, CO2 and water vapor atmosphere, high-carbon ferromanganese powders were decarburized in a fluidized bed. When the temperature is respectively higher than 273, 1226 and 1312 K, the gas-solid decarburization reaction will occur between ferromanganese carbide on the surface of the high-carbon ferromanganese powders and different gas decarbonizers. Since metal manganese is easy to be oxidized by O2, CO2 or water vapor, the decarburization reaction will transfer into a solid-solid phase reaction of ferromanganese carbide and ferromanganese oxide, promoting external diffusion of carbon to achieve a further decarburization of high-carbon ferromanganese powders.     

高速钢淬火脱碳的检测与控制

针对单纯用化验盐浴中氧化钡含量的方法检查高速钢盐浴淬火脱碳的情况,介绍了在高速钢工具生产中应用的钢箔法检测脱碳和根据钢箔法开发的脱碳检测仪。同时还介绍了可以清晰显示高速钢脱碳层的两种金相法和显微硬度压痕法。     

包装热处理

本文简述了包装热处理的实施方法、适用范围及注意事项。以5CrNiMo、GCr15钢零件为例,包装热处理能减少工件表面氧化和脱碳的缺陷,是一种简便、低成本的工艺。