Oxide scale characterization of ferritic stainless steel and its deformation and friction in hot rolling

The oxidation kinetics of ferritic stainless steel 430 was studied in dry and humid air at 1090 °C by Thermo Gravimetric Analysis (TGA). Different atmospheres and heating times were adopted for reheating to obtain different compositions and thickness of the oxide scale. Hot rolling was performed on a 2-high Hille 100 experimental rolling mill at various reductions. Oxide scale thickness and composition were analysed with optical microscopy (OM), scanning electron microscope (SEM) and X-ray diffraction (XRD). The surface profiles were examined by a digital microscope, and the topographic features of the thin oxide scale surface were examined with an atomic force microscope (AFM) before and after rolling. The oxide scale surface and steel/oxide interface roughness were measured after rolling. Inverse calculation of the coefficient of friction was employed to analyse and the effect of oxide scale on friction in hot rolling. The coefficient of friction depends not only on the thickness of the oxide scale, but also on its composition and surface topography before hot rolling.     

A304不锈钢薄板激光焊接的光谱分析

为了进一步分析不同焊接参数对A304不锈钢薄板激光焊接效果的影响,该文在不同的焊接参数和激光输出方式下,采用AvaSpec-2048型光纤光谱仪对A304不锈钢薄板激光焊接的电弧进行了光谱分析。研究结果表明,激光功率、焊接速度和激光输出方式对激发出特征谱线的元素的种类和激光等离子体中元素的含量有一定的影响。     

双相不锈钢复合钢板焊接

对双相不锈钢复合钢板的焊接特点、焊接材料、焊接方法与焊后热处理进行了重点分析与讨论     

316LN不锈钢低速率应变下的热变形行为

目前, 对316LN不锈钢在低速率应变下的热变形行为研究很少. 本文选用工业316LN不锈钢, 通过Gleeble-3800热模拟试验机进行了600-1 100 ℃温度下, 应变速率为3×10-3 s-1的热压缩试验, 得到了真应力-应变曲线. 通过分析真应力-应变曲线和试样的微观组织, 得到了如下结论: 1 000 ℃和稍高温度是适于低速率应变下316LN不锈钢加工的温度.     

不锈钢垫片的磨削加工

介绍了组合砂轮磨削不锈钢垫片时砂轮对加工表面质量和磨削力的影响。     

时效工艺对2205双相不锈钢组织与力学性能的影响

研究了时效温度和时间对2205双相不锈钢组织及力学性能的影响,并对其断口形貌进行了分析。结果表明,2205不锈钢在时效处理中析出相σ相的形核位置、形态及数量与时效温度和时间有很大关系。时效温度高时,σ相在δ/γ相界和δ相内同时形核、生长,并且易形成块状;温度低时,σ相则偏聚在δ/γ相界生核,然后向δ相内生长,σ相易形成片状组织;同时,σ相的数量也会随着时效时间的延长而增加。475℃和600℃时效后双相不锈钢的强度明显提高,韧性略有降低,微观断口以韧窝为主。750℃时效后强度有所提高,韧性明显降低,微观断口以解理平面为主。     

有机硅涂层对316不锈钢的防护

研究了316不锈钢在高温（400℃）盐和水蒸气综合作用下的腐蚀行为及添加Al粉和Ti粉的有机硅涂层对不锈钢的防护作用。结果表明，316不锈钢裸样发生了较为严重的腐蚀。刷涂了有机硅涂层的316不锈钢在相同的条件下没有发生腐蚀，涂层对316不锈钢具有优异的防护作用．讨论了有机硅涂层的防护机理。     

不锈钢复合管液压胀接装置

介绍了一种不锈钢复合管液压胀接装置的工作原理及其技术特点。     

2205双相不锈钢管焊接工艺评定

铁素体-奥氏体双相不锈钢,简称即双相不锈钢(DSS),具有优良的力学性能和耐蚀性能,2205(也称22Cr)双相不锈钢管材在石油及天然气工业、海洋工程、化学工业等行业具有广泛的用途。该材料焊接有许多技术特点,工艺参数对接头的组织和性能有很大影响。对D508×15.9mm规格钢管制管纵缝和现场环焊缝焊接工艺评定进行介绍。     

304不锈钢A-TIG焊的试验研究

主要研究在304不锈钢焊接时涂敷活性焊剂和未涂敷活性焊剂对焊缝成形的影响。试验结果表明304不锈钢采用A-TIG焊时,涂敷活性焊剂的焊缝熔深显著增加,熔宽有所减小;活性剂使熔池横截面形状发生明显变化,即焊缝上部比较宽、中下部变得很窄,这主要是由表面张力梯度的变化引起的。     

2205双相不锈钢氢致开裂行为的试验分析与模型预测

开展了2205双相不锈钢(Duplex stainless steel,DSS)氢致开裂(Hydrogen assisted cracking,HAC)行为的研究,考察了组织形态对2205双相不锈钢中氢致裂纹萌生和扩展的影响.结果表明,横向组织中的氢致裂纹扩展的长度比纵向组织中的裂纹更明显,裂纹优先萌生的位置在铁素体相...     

超临界不锈钢材质铸件的涂料开发和应用

从超临界汽轮机用ZG1Cr10MoVNiN不锈钢铸件对于新型涂料的要求方面进行了阐述,主要介绍了一种适合于超临界汽轮机用不锈钢铸件涂料开发和利用,并且通过实际生产的对比试验,证明了这种新型涂料的作用和应用的可行性。     

316L不锈钢的车削精加工研究

笔者对316L不锈钢材料的切削加工特点进行分析,并从刀具材料的选用以及切削用量、切削液的选择3方面对316L不锈钢零件的车削精加工进行了分析和研究.     

An exact solution for the elastic/plastic bending of anisotropic sheet metal under conditions of plane strain

A theoretical analysis for the elastic/plastic bending of sheet metal exhibiting a state of normal anisotropy is considered in this paper, assuming a plane strain condition to exist in the deformation process. The material is supposed to yield according to Hill's quadratic yield criterion and its associated normality rule of plastic flow. The relationship between the bending couple and the curvature of the bent sheet is presented in a graphical form that reveals the influence of anisotropy and strain-hardening on the bending characteristic of the sheet metal. The results indicate that the elementary bending theory significantly overestimates the magnitude of the bending couple to produce a given elastic/plastic curvature of the bent sheet.     

2Cr13不锈钢温挤压工艺探讨

2Cr13钢是一种马氏体不锈钢。退火后硬度较高。冷挤压很困难。介绍通过选择合理的温挤压工艺参数，研制高效的温挤压涂料等，成功地获得了良好的挤压件方法。     

不锈钢复合管的端部密封焊接

介绍了一种可实现不锈钢复合管可靠焊接的管端密封焊接技术。     

Influence of temperature on a low-cycle fatigue behavior of a ferritic stainless steel

The main objective of this study is to reveal the effect of dynamic strain ageing (DSA) on a ferritic stainless steel with detail relation to monotonic and cyclic responses over a wide range of temperatures. For assessing the effect of strain rate on mechanical properties, tensile test results are studied at two different strain rates of 2×10^?3/s and 2×10^?4/s. Typical responses of this material are compared with other alloy in literatures that exhibits DSA. Serrations in monotonic stress-strain curves and anomalous dependence of tensile properties with temperatures are attributed to the DSA effect. The low cycle fatigue curves exhibit prominent hardening and negative temperature dependence of half-life plastic strain amplitude in temperatures between 300°C–500°C which can be explained by DSA phenomenon. The regime for dependence of marked cyclic hardening lies within the DSA regime of anomalous dependence of flow stress and dynamic strain hardening stress with temperature and negative strain rate sensitivity regime of monotonic response. It is believed that shortened fatigue life observed in the intermediate temperature is mainly due to the adverse effect of DSA. An empirical life prediction model is addressed for as-received material to consider the effect of temperature on fatigue life. The numbers of load reversals obtained from experiment and predicted from fatigue parameter are compared and found to be in good agreement.     

不锈钢复合钢板油箱的焊接

针对A3+1Cr18Ni9Ti不锈钢复合钢板焊接时容易出现的问题进行分析,选用了合理的焊接材料及工艺方法,确保了油箱的焊接质量.     

Nonlinear cavitation erosion of stainless steel in mercury versus applied power

The cavitation erosion rate for 316 stainless steel in mercury was found to increase in a nonlinear fashion with the maximum applied power. In addition, the incremental increase in erosion was observed to decrease with increased power in water, yet increased six to seven times when mercury was used as the cavitating fluid. This revised version was published online in July 2006 with corrections to the Cover Date.     

不锈钢管接头精密成形的工艺分析与实验研究

不锈钢管接头截面积变化大，成形和脱模困难。本文对其塑性加工工艺方案进行分析比较，并通过工艺实验，验证工艺分析结果。该零件采用温挤压成形可以获得较好的技术经济效益；一次正挤压效率高，工艺力大；正挤-镦粗复合工艺则工艺力小，但效率较低。