Fatigue strength of high strength dual-phase steel sheet

Fatigue tests have been carried out on lean-alloyed dual-phase steels with tensile strengths ranging from 300–800 MPa. Smooth specimens and specimens with punched holes were tested. The fatigue strength of dual-phase steel was found to be similar to that of other types of steel (eg solution hardened or microalloyed steels) of equal tensile strength. The fatigue strength increases with increasing yield strength. For notched specimens it is also related to the yield ratio. Work and bake hardening increase the fatigue strength of smooth specimens in proportion to the increase in yield strength. For notched specimens this effect is less and is dependent on the yield ratio. Bake hardening of material which was not work hardened also increased the fatigue strength. The notch sensitivity of low yield ratio dual-phase steel is found to be low. The notch sensitivity seems to increase with increasing yield ratio.     

电子探针分析用标样：Fe—C合金标样组的研制

作者成功地制作一组电子探针定量分:析碳用的Fe-C合金(0.156～0.978％C)标样。标样的所有指标均达到了GB—4930—85标准技术指标。这表明,这是一组定量电子探针分析碳钢和低合金钢中碳的很好的标样。文中详细地介绍了标样的制作方法和检测结果。     

预先冷变形对09SiMnCrMo钢临界区奥氏体化过程的影响

举文研究了09SiMnCrMo 钢预先冷变形组织在临界区加热时的奥氏体化过程。结果表明,临界区奥氏体化过程可分为二个阶段,冷变形使第一阶段提前,使第二阶段奥氏体含量出现一个超出其平衡量的最大值。温度的不同会导致奥氏体形核、铁素体再结晶以及珠光体内渗碳体的球化发生先后变化。     

冷轧无取向电工钢的点阵畸变储能及其对再结晶织构的影响

用X-射线衍射方法研究了不同压下率条件下冷轧无取向电工钢中各个晶体学方向的点阵畸变储能及其对再结晶织构的影响。结果表明：①当压下率分别为74％、77％和85％时，各晶体学方向的点阵畸变及其储能与各自的弹性模量之间总体上呈负相关关系；②冷轧压下率影响着各位向储能的大小，从而影响再结晶织构的强度。这一结果支持“定向成核”再结晶织构形成理论；③随冷轧压下率的增加，钢带单位面积内的总储能也相应增加。     

15MnTi钢的中子辐照效应

介绍了１５ＭｎＴｉ钢的母材，焊缝及其热影响区在不同注量的快中子辐照后，材料的机械性能变化的情况，根据试验结果表明，辐照温度为５０℃，快中子注量在１．０×１０＾１８ｃｍ＾－２到６．０×１０＾１８ｃｍ＾－２之间，１５ＭｎＴｉ钢的脆性转变温度增量△Ｔｃｖ与积分快中子注量的经验关系公式。     

The relevance of wear-mechanism maps to mild-oxidational wear

The presence of oxygen in the environment in which a steel sliding system operates will promote a mild form of wear with wear debris consisting mainly of iron oxides. Of the oxidation-dominated mechanisms, mild-oxidational wear (the prefix describes the extent of oxidation and not the wear rate) has been most extensively investigated. In this paper, examples will be used to show that the wear-mechanism map for the unlubricated sliding of steels can adequately predict the occurrence of mild-oxidational wear and the trend of wear rates as well as describe the resultant features on the worn surfaces. It is also shown that this map is relevant to delamination wear and to test geometries other than the pin-on-disk configuration. It is suggested that the more-recently constructed wear maps for aluminium and magnesium alloys could similarly be used to predict the wear characteristics of these alloys during sliding.     

Effect of alloying additions onK ISCC of ultrahigh strength NiSiCr steel

The effect of alloying additions viz. cobalt, molybdenum, cerium and a combination of cobalt and molybdenum, on theK _ISCC of NiSiCr steel in 3·5% NaCl aqueous solution was studied. Addition of cobalt to NiSiCr steel resulted in an increase in theK _ISCC whereas molybdenum addition decreased theK _ISCC. Cerium addition did not affect theK _ISCC while the combination of cobalt and molybdenum resulted in an increase in theK _ISCC although not as much as in the case of cobalt addition. The effect of alloying elements onK _ISCC could be attributed to their effect on the critical fracture stress and yield strength.     

硅在高速钢中的使用原则及含硅高速钢的发展

阐述了硅在高速钢中的影响进规律和作用及使用原则，硅影响二次硬化的△Ｗ判据，分析了比较了硅、钴和铝高速钢中的不同作用，介绍了两种新型的含硅高速钢。     

Characterization of interfacial friction in coated sheet steels: influence of stamping process parameters and wear mechanisms

By means of a tensile strip testing system, the nature of interfacial friction in stamping operations were investigated for three different coated sheet steels. Friction coefficient measurements were taken at seventeen distinct operating conditions by varying the sheet strip coating material (lead and zinc), applied lubricant (oil-base lubricants and greases) and pin radii (10 and 20 mm). In addition to determining the friction coefficient, the surface roughnesses of the sheet strips were measured before and after the completion of each test. From the experimental results, several relationships were ascertained for the role of the microscopic wear in determining the character of interfacial friction during stamping processes.     

工模具钢的一种节能高效表面渗硼技术

以柱状电极为一极并置于渗罐的中央,以渗罐壁作为另一电极,渗剂与试样置于两极之间,对T7、T12及W18Cr4V3种工模具钢进行中、低温下的交流电场增强粉末法渗硼。结果表明：施加4A、30-50V的交流电场可以显著促进工模具钢在中低温外热下的渗硼过程,渗层厚度较相应常规渗硼的提高70%以上,渗硼层组织同时也有所改善;所研究的渗硼新技术可显著降低渗硼处理加热温度,减少渗硼时间,节约能源,降低渗硼成本。对交流电场在粉末法渗硼中的作用机制进行了初步分析。