碳、硅含量对重载车轮钢显微组织的影响

利用金相显微术、扫描电镜、透射电镜以及X射线衍射测量技术研究碳、硅含量对重载车轮钢显微组织的影响。结果表明:重载车轮钢的显微组织由珠光体和少量先共析铁素体组成,适当降低碳含量、增加硅含量不仅使珠光体含量减少,而且导致珠光体的片层间距增大;与珠光体团内层片状组织相比,珠光体团界处的渗碳体不再呈片状、而是以颗粒状不连续分布,同时渗碳体含量相对较少。     

环口板加固T型方钢管节点在轴压作用下极限承载力的参数分析

为了研究环口板加固对T型方钢管节点在支管承受轴向压力作用下的极限承载力的影响,本文运用前期工作中所采用的有限元模型建立方法,对320个环口板加固T型方钢管节点进行了参数分析。参数包括支管和主管的宽度比β,主管的宽度与厚度比2γ,环口板与主管厚度比τc和环口板与支管宽度比lc/d1。参数分析结果表明:通过对环口板的宽度和厚度进行适当的组合,可以显著提高节点的承载力。然后将有限元模拟得到的极限承载力结果与前期工作中推导出的极限承载力公式的计算结果进行对比,给出了极限承载力计算公式的适用范围。     

Effect of deteriorated microstructures on stress corrosion cracking of X70 pipeline steel in acidic soil environment

In order to investigate stress corrosion cracking (SCC) of X70 pipeline steel and its weld joint area in acidic soil environ-ment in China, two simulating methods were used: one was to obtain bad microstructures in heat affected zone by annealing at 1300°C for 10 min and then, quenching in water; the other was to get different simulating solutions of acidic soil in Yingtan in south-east China. The SCC susceptibilities of X70 pipeline steel before and after quenching in the simulating solutions were analyzed...     

提高品种钢质量推动精益化管理

介绍了湘钢以82B为代表的品种钢质量控制方面的作法与经验,以及以其为切入点,全面推行产品质量的精益化管理模式.     

The State-of-Art and Development Trends of HSLA Steels in China

During the last decade,the adjustment of product segments always is a very important task of iron industry,and upgrading of steel products has been impelled actively by Chinese iron and steel industry.With rapidly increasing of iron & steel production,a series of research achievements have been made in the technology area of high strengthtoughness steel,and also have been applied successfully in the actual production,e.g.the technology of fine grain and ultra-fine grain steels,the technology for the control of microalloying precipitates.Further,It is an important strategic goal of "Twelfth Five-year Plan" for Chinese iron and steel industry that the adjustment of steel product segments and meeting the requirements for upgrading of domestic and oversea equipment manufactory industry.Adopting HSLA steel with better performance,instead of plain steel,could save steel consumption largely,and also release pressures from resource,energy and environment.Without doubt,it is the only way to realize the sustained development of Chinese iron and steel industry by popularizing the application of HSLA steels vigorously.     

GCr15钢制钉模复合强韧化工艺研究

通过失效分析和脆断机理研究，对制钉模的失效原因进行了深入分析，在此基础上对复合处理工艺进行了改进；改进后复合处理的G015钢制钉模具有较高的强度和韧性，基本上避免了早期脆性断裂。     

修正的抗剪强度参数可靠度分析方法

在抗剪强度参数可靠度分析中,针对摩尔库仑强度准则方程表现出的非线性,给出了修正的可靠度分析方法.首次选取泰勒级数的部分二次项,用一个距原点最近点处拟合的超低维曲面近似极限状态面.推导了修正的可靠度计算公式,较原有的可靠分析方法(JC法),计算精度得到进一步的提高.     

超声回弹综合法检测修正的必要性分析

使用超声回弹综合法检测建筑实体混凝土强度,当混凝土构件检测值和测强曲线有较大差异时,采用钻芯修正能更真实地反映建筑实体质量。     

循环荷载作用下钢结构滞回性能的数值模型

提出了“塑性铰有限分布”的数值模型用以分析钢结构在循环荷载作用下的滞回性能。经与试验结果比较表明模型简单、易于实施，待进一步完善后，可直接用于对梁及压弯构件的模拟。     

Effect of niobium on thermal stability and impact toughness of Nd-Fe-B magnets with ultra-high intrinsic coercivity

The effects of Nb on the thermal stability and impact toughness of ultra-high intrinsic coercivity of Nd-Fe-B magnets were investigated.The results showed that the addition of Nb could improve the thermal stability,and obviously increased the impact toughness of sintered Nd-Fe-B magnets.The optimum thermal stability of sintered Nd-Fe-B magnets was obtained when the content of Nb was 1.0 at.%.The maximum impact toughness of sintered Nd-Fe-B magnets was obtained when the content of Nb was 1.5 at.%,but the magnetic properties of sintered Nd-Fe-B magnets drastically deteriorated when the content of Nb increased from 1.0 at.% to 1.5 at.%.The microstructure showed that overfull Nb addition made many ultra-fine grains get together,which led to the density of sintered Nd-Fe-B magnets decline and drastically deteriorated the magnetic properties of sintered Nd-Fe-B magnets.