Modification of Inclusions in Liquid Iron by Mg Treatment

Effect of Mg addition on the compositions of inclusions were studied. The results show that Mg can minimize the inclusions of steel obviously. Under the present condition, Mg deoxidation products of low-S content experimental steel would be changed in the order of Al₂O₃→MgAl₂O₄→Mg→Al–O–S→Mg–O–S. Mg deoxidation products of high-S content experimental steel generate Mg–S(–O)+MnS type inclusions, except for usual oxysulfide. And it is consistent with the results of thermodynamics calculation. Mg is preferred to react with oxide, compared with sulfide. The reaction reaches the equilibrium after 1 min or 5 min. It shows that the number and diameter of inclusions in all experimental steel samples are well under control, helping to improve the properties of steel.     

蜂窝陶瓷蓄热体的热应力场数值模拟

对普通正方形格孔蜂窝蓄热体和夹角圆弧过渡正方形格孔蜂窝蓄热体的热应力场进行了数值模拟计算与对比分析.结果表明,夹角圆弧过渡正方形格孔蜂窝蓄热体的低应力区域更大,应力分布也更均匀;数值模拟结果能够指导蓄热体的结构优化设计.     

热镀锌机组钢卷运输系统功能研究及结构优化

介绍了武钢冷轧热镀锌机组钢卷运输系统中的重要辅助设备钢卷小车的布置形式和功能,总结了目前钢卷小车存在的结构缺陷及优化方法,对实现现场钢卷运输系统的稳定高效运行提供了可供借鉴的经验。     

用氧化镁坩埚真空熔炼优质低碳低氧钢

为了降低氧化钙坩锅冶炼优质低碳低氧钢的生产成本,在50kg真空感应炉上开展氧化镁坩埚替代氧化钙坩锅冶炼优质低碳低氧钢的工艺试验。试验结果表明:随炉加入5g底碳可以用于钢液脱氧,不会造成钢液增碳;利用SiO挥发脱氧的特点,在真空度1Pa时,加入硅铁,抽气10min,成功用氧化镁坩埚冶炼出w(C)为9×10-6～14×10-6、w(O)为14×10-6～18×10-6的优质低碳低氧钢。     

Effects of Cold Rolling Reduction on Retained Austenite Fraction and Mechanical Properties of High-Si TRIP Steel

 Transformation-induced plasticity-aided steel ［TRIP steel (0. 4C-1. 5Si-1. 5Mn)］ was rolled at room temperature to different thickness reductions (0, 4%, 10%, 20%, 40%, and 60%). The mechanical properties, microstructure and austenite fractions of the rolled samples were measured by tensile test, electron back scattered diffraction (EBSD) and X-ray diffraction (XRD) for each rolling. The deformation behavior was studied based on the analysis of the mechanical properties and microstructure of steel after tensile deformation, aiming at understanding the effects of cold rolling reduction on the decay behavior of the austenite and the change of mechanical properties of the TRIP steels. It was found that increasing rolling reduction increases the yield stress gradually but decreases the total elongation significantly. It is very interesting that after 10% rolling reduction the yield stress is about 1000 MPa but still with 20% total elongation, which gives an excellent combination of yield strength and ductility. Based on the XRD results, it was revealed that in both rolling and tension the austenite volume fraction monotonically decayed with the increase of rolling strain, but the decaying rate is faster in tension than in rolling, which may be ascribed to the higher temperature in rolled specimens than in the tensioned ones during deformation. Experimental results and theoretical reasoning indicate that the decreasing trend of austenite volume fraction with strain can be formulated by a unique equation.     

利用基氏流动度指标评价焦煤质量的研究

通过基氏流动度指标、镜质组反射率的测定和焦炭显微结构的研究,探讨了最大流动度与焦炭显微结构之间的关系,并提出利用软化温度和最大流动度相结合的方法对焦煤煤质进行评价。     

TRIP600 高强钢的点焊工艺研究

对1．8mm规格的TRIP600钢进行了点焊试验、拉剪试验和接头的金相分析,研究了焊接电流、焊接时间等点焊工艺参数对接头力学性能的影响。结果表明,焊接时间为0．20、0．24、0．30S,TRIP600钢的可焊电流范围分别为11-12、10．5～12、10-11．5kA,拉剪试验失效模式为扣式或母材撕裂、且无飞溅的焊点,拉剪力达到27-30kN。     

热连轧高强钢板形瓢曲原因分析

高强钢钢板瓢曲已严重制约了其在汽车行业的应用,对其生产工艺进行分析,发现冷却不均引起的残余内应力是造成钢板分条后瓢曲的主要原因。通过调整钢板上下表面冷却水水量、采用间断式冷却模式、进行堆垛缓冷,显著降低了高强钢钢板的残余应力,使分条后钢板不平度不大于6 mm/1 700 mm的合格率提高至85%。     

武钢炼钢总厂三分厂转炉负能炼钢实践

简述转炉实现负能炼钢的工艺流程,介绍武钢炼钢总厂三分厂实现转炉负能炼钢的实际情况及其所采取的措施。     

二次冷轧镀锡板的合金-锡电偶合研究

采用电化学方法研究武钢研制的二次冷轧镀锡板合金—锡电偶合ATC值和合金锡量,并利用扫描电镜观察合金层的形貌。研究结果表明,武钢二次冷轧镀锡板ATC平均值≤0．12μA／cm^2,合金锡量在0．9g／m^2以上,合金层形貌致密连续,ATC值达到国标GB／T2520-2008和美国标准ASTMA623M-06a合金-锡电偶合指标要求。