共查询到18条相似文献，搜索用时 15 毫秒
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Manganese is an essential alloying element in advanced austenitic stainless steels with specific properties such as high resistance to harsh corrosive environments, high strength or low material costs. These materials are often used for welded constructions which have to be highly corrosion resistant. Hence it has to be ensured that the heat input during welding does not initiate the precipitation of chromium carbide resulting in a susceptibility to intergranular corrosion. This leads to the question whether the sensitization behaviour of manganese‐alloyed austenitic stainless steels is comparable to that of the well‐known conventional chromium nickel austenites. In the present work the effect of heat‐input on the susceptibility of the CrNi‐steel 1.4301 and the CrNiMn‐steel 1.4376 to intergranular corrosion (IGC) was considered. Investigations were carried out by corrosion testing in the so‐called Strauss‐Test to elucidate the effect of the annealing temperatures on the microstructure. Furthermore, the influence of heat treatment on the mechanical properties was evaluated by tensile testing. As a result, it could be demonstrated that manganese‐alloyed austenitic stainless steels like grade 1.4376 exhibit a sensitization behaviour very similar to the conventional austenitic steel grades. The same kinds of tests on intergranular corrosion resistance can be applied for both types of materials. 相似文献
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以聚乙二醇/环氧树脂（PEG-EP）为粉末表面改性剂,聚甲醛系树脂（POM）为粘结剂体系,混炼制备316L不锈钢粉末注射成型喂料,并通过硝酸催化脱脂后烧结得到316L烧结样品。通过傅里叶红外光谱仪、扫描电子显微镜、接触角测量仪、旋转流变仪、万能材料试验机、金相显微镜、碳硫分析仪、显微硬度计等研究了PEG-EP对316L不锈钢粉末的包覆效果以及PEG-EP表面处理对316L不锈钢粉末注射成型喂料和烧结样品性能的影响。结果表明,PEG-EP成功包覆在316L粉末表面,改善了316L不锈钢粉末与聚甲醛的界面相容性,提高了喂料流动的性能、生坯的力学性能和烧结样品的力学性能及硬度。当添加PEG-EP质量分数为0.662%、粉末装载量（体积分数）为63%时,316L注射生坯的拉伸强度、断裂伸长率、弯曲强度分别为10.57 MPa、8.38%、21.24 N·(mm2)−1;烧结样品晶粒尺寸为50.8 μm,最大抗拉强度和维氏硬度为688 MPa和HV 151,烧结样品的综合性能最佳。 相似文献
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A.K.Lakshminarayanan 《钢铁研究学报(英文版)》2009,16(5):66-0
The present investigation is aimed at to study the effect of welding processes such as shielded metal arc welding, gas metal arc welding and gas tungsten arc welding on tensile and impact properties of the ferritic stainless steel conforming to AISI 409M grade. Rolled plates of 4 mm thickness were used as the base material for preparing single pass butt welded joints. Tensile and impact properties, micro hardness, microstructure and fracture surface morphology of the welded joints have been evaluated and the results are compared. From this investigation, it is found that gas tungsten arc welded joints of ferritic stainless steel showed superior tensile and impact properties compared with shielded metal arc and gas metal arc welded joints and this is mainly due to the presence of finer grains in fusion zone and heat affected zone. 相似文献
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G Magudeeswaran V Balasubramanian G Madhusudhan Reddy T S Balasubramanian 《钢铁研究学报(英文版)》2008,15(6):87-0
Quenched and tempered steels are prone to hydrogen induced cracking in the heat affected zone after welding. The use of austenitic stainless steel consumables to weld the above steel was the only available remedy because of higher solubility for hydrogen in austenitic phase. In this investigation, an attempt was made to determine a suitable consumable to replace expensive austenitic consumables. Two different consumables, namely, austenitie stain less steel and low hydrogen ferritic steel, were used to fabricate the joints by shielded metal are welding （SMAW） and flux cored arc welding （FCAW） processes. The joints fabricated by using low hydrogen ferritic steel consumables showed superior transverse tensile properties, whereas joints fabricated by using austenitic stainless steel consumables exhibited better impact toughness, irrespective of the welding process used. The SMAW joints exhibited superior mechanical and impact properties, irrespective of the consumables used, than their FCAW counterparts. 相似文献
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The effect of welding processes such as shielded metal arc welding, gas metal arc welding and gas tungsten arc welding on tensile and impact properties of the ferritic stainless steel conforming to AISI 409M grade is studied. Rolled plates of 4 mm thickness were used as the base material for preparing single pass butt welded joints. Tensile and impact properties, microhardness, microstructure and fracture surface morphology of the welded joints have been evaluated and the results are compared. From this investigatio.n, it is found that gas tungsten arc welded joints of ferritic stainless steel have superior tensile and impact properties compared with shielded metal are and gas metal arc welded joints and this is mainly due to the presence of finer grains in fusion zone and heat affected zone. 相似文献
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The sequence of structural changes produced in two deformed microstructures of austenitic stainless steel elaborated by a multipass unidirectional cold rolling (CR) and a two-step one, to a 75% thickness reduction, is followed by dilatometric experiments. The two materials show different dilatometric behaviors. X-ray diffraction and microhardness measurements are performed to underlie the observed dilatometric behaviors. The material subjected to multipass unidirectional CR shows an unusual dilatometric behavior. The first heating stage leads to the occurrence of the recovery reaction in competition with the ε-martensite reversion. When the temperature increases between 550 and 780 °C, the reversion of deformation-induced α-martensite takes place and leads to a complicated dilatometric anomaly. Further increase in temperature leads to the occurrence of the recrystallization transformation. However, the material subjected to two-step CR shows a quite usual dilatometric behavior which is explained by the occurrence of several reactions in the following order: 1) T < 300 °C, the recovery reaction, 2) 300 < T < 680 °C, the ferro- to paramagnetic transformation of α-martensite, the reversion of ε-martensite, and the athermal reversion of α-martensite, 3) 680 < T < 760 °C, thermal reversion of DIM, and then 4) at T > 760 °C, the recrystallization. 相似文献
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The fraction and microstructure of spontaneous and deformation‐induced martensite in three austenitic stainless steels with different austenite stability have been investigated. Samples were quenched in brine followed by cooling in liquid nitrogen or plastically deformed by uniaxial tensile testing at different initial temperatures. In‐situ ferritescope measurements of the martensite fraction was conducted during tensile testing and complemented with ex‐situ X‐ray diffractometry. The microstructures of quenched and deformed samples were examined using light optical microscopy and electron backscattered diffraction. It was found that annealing twins in austenite are effective nucleation sites for spontaneous α'‐martensite, while deformation‐induced α'‐martensite mainly formed within parallel shear‐bands. The α'‐martensite formed has an orientation relationship near the Kurdjumov‐Sachs (K‐S) relation with the parent austenite phase even at high plastic strains, and adjacent α'‐martensite variants were mainly twin related (<111> 60° or Σ3). 相似文献
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在304L不锈钢的成分基础上,添加不同质量分数(0.072%~0.132%)的Ag,并对其热轧板进行固溶处理和冷轧,发现材料的显微组织均为均匀的奥氏体组织,且随着Ag含量的增加,屈服强度及伸长率变化均不明显。利用OM、SEM和TEM观察不同变形条件下材料中Ag颗粒变化,发现Ag颗粒主要为材料冶炼时未熔入到基体内的Ag,其在基体中弥散分布,呈椭球形或球形;Ag颗粒有2种存在形式,即几纳米到几十纳米的富Ag相、由多个纳米级Ag相团簇聚集在一起形成的几百纳米到几微米的Ag颗粒聚集物。另外,热轧后,富Ag颗粒聚集物沿轧制方向变成带状、棒状,部分分裂为椭球状或球状;进一步冷轧变形后,富Ag颗粒的尺寸减小,且变形量越大,Ag颗粒尺寸越小。 相似文献
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Fundamental investigation of continuous drive friction welding of austenitic stainless steel (AISI 304) and low alloy steel (AISI 4140) is described. The emphasis is made on the influence of rotational speed on the microstructure and mechanical properties such as hardness, tensile strength, notch tensile strength and impact toughness of the dissimilar joints. Hardness profiles across the weld show the interface is harder than the respective parent metals. In general, maximum peak hardness is observed on the stainless steel side, while other peak hardness is on the low alloy steel side. A trough in hardness distribution in between the peaks is located on the low alloy steel side. Peak hardness on the stainless steel and low alloy steel side close to the interface increases with a decrease in rotational speed. All transverse tensile joints fractured on stainless steel side near the interface. Notch tensile strength and impact toughness increase with increase in rotational speed up to 1500 r/min and decrease thereafter. The mechanism of influence of rotational speed for the observed trends is discussed in the torque, displacement characteristics, heat generation, microstructure, fractography and mechanical properties. 相似文献
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This paper presents the comparative evaluation of microstructural features and mechanical properties of a friction stir welded (solid‐state) and gas tungsten arc welded (fusion weld) 409 M grade ferritic stainless steel joints. Optical microscopy, microhardness, transverse tensile and impact tests were performed. The coarser ferrite grains in the base material are changed to very fine grains consisting of a duplex structure of ferrite and martensite due to the rapid cooling rate and high strain induced by severe plastic deformation caused by frictional stirring. On the other hand, grain growth was observed in the fusion zone as well as heat affected zone of the gas tungsten arc welded joint resulting in deterioration of mechanical properties. 相似文献
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HQ130＋QJ63高强钢焊接接头的组织与性能 总被引：1，自引：0，他引：1
采用光镜，电镜，冲击和拉伸等试验方法，对气体保护焊“低强匹配”焊材焊制的ＨＱ１３０＋ＱＪ６３高强钢焊接接头的显微组织和力学性能进行了试验研究，并采用模拟焊接热循环的方法研究了不同峰值温度和冷却时间对ＨＱ１３０钢热影响区（ＨＡＺ）组织和冲击韧性的影响，试验结果表明，受焊接热循环影响，ＨＱ１３０钢ＨＡＺ存在回火软化区，该区域软化或失强最大的部位在峰值加热温度为Ａｃ１附近。在ＨＡＺ峰值温度Ａｃ１～Ａｃ３ 相似文献
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Bryan Ramiro Rodriguez-Vargas;Giulia Stornelli;Argelia Fabiola Miranda Pérez;Andrea Di Schino; 《国际钢铁研究》2024,95(5):2300798
Duplex stainless steels (DSS), due to their high corrosion resistance, primarily attributed to their austenite-ferrite duplex microstructure, are widely used in industrial sector such as petrolchimical and gas natural industries. Maintaining this microstructure is crucial during manufacturing processes, including welding which presents the challenge of minimizing ferritization in the heat-affected zone (HAZ) or weld zone (WZ), as it can significantly reduce their corrosion resistance. This work aims to describe the influence of nitrogen gas in the Ar–N2 shielding atmosphere when depositing beads on 2205 DSS plates, using a gas tungsten arc welding (GTAW) process. It is observed that at low nitrogen load (98%Ar–2%N2), the austenite content reaches 49% in WZ and 29% in HAZ. When the nitrogen percentage is increased (50%Ar–50%N2), the austenite content rises to 67% and 37%, respectively. The joint is evaluated macro- and microstructurally to observe the atmosphere impact on weld bead geometry and microstructural development. Additionally, hardness is assessed throughout the weld bead. The work demonstrates that, with a 50%Ar–50%N2 shielding gas mixture, it is possible to limit the formation of ferrite in the WZ and HAZ of DSS during the welding process, without altering the microhardness trend of the welded joint. 相似文献
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以WNQ690钢为研究对象,采用气保护焊接工艺,焊接线能量控制在15kJ／cm,WER70NH匹配WNQ690钢进行焊接,研究WNQ690钢焊接性能及焊接组织结构。接头抗拉强度为750MPa,冷弯性能优良,焊缝-40℃平均冲击功为137J,熔合线及热影响区冲击功均达到较高水平,焊接接头的HV10硬度在234-300之间,说明WNQ690钢淬硬倾向较小。WNQ690钢材的组织为回火贝氏体,焊接接头过热区组织为贝氏体,焊缝中含有较多的针状铁素体和少量的先共析铁素体,焊接热影响区的细小贝氏体组织使焊接热影响区具有较高的冲击韧性。 相似文献
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因榍石在变质岩中含量太少,晶体光学特征不明显,利用偏光显微镜及X射线衍射(XRD)等鉴定技术不易确定。实验利用扫描电镜/能谱仪检测矿物所含元素的种类,确定各元素的大致含量,根据定性分析结果,调用相应的标准样品数据文件,建立所测样品的文件清单。运用Casino程序和Quanta程序,据所测元素的强度值计算出样品中各元素的质量分数,依据矿物化学式中阴阳离子电价平衡的配比规律,计算出所测样品的化学组成。分析结果表明,所测8个样品中SiO2质量分数在33.36%～34.10%之间,CaO质量分数在25.85%～27.00%之间,(TiO2+Fe2O3+Al2O3+CrO2) 质量分数在39.31%～40.45%之间,与榍石主要化学成分基本一致。实验表明,同一件榍石样品平行测定10次,O、Si、Ca、Ti、Fe元素测定结果的相对标准偏差(RSD)依次为0.23%、0.30%、0.28%、0.26%、1.6%,精密度符合要求;经验证,实验方法的测定结果与电子探针波谱法测定结果相符。 相似文献
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以粉末冶金高铬铸铁和低碳钢为原材料,采用多道次手工钨极氩弧焊,研究了焊接电流对焊缝组织演变和力学性能的影响,提出了焊接接头组织演化模型,并探讨了其断裂机理。结果表明,焊接接头的抗拉强度在焊接电流为140 A时达到538.1MPa,分别是烧结高铬铸铁和低碳钢抗拉强度的95.3%和97.4%。由于二次回火和合金元素扩散/偏析的作用,焊接接头的显微硬度在水平方向上由高铬铸铁一侧向低碳钢一侧逐渐降低,而在垂直方向则呈M形分布。当焊接电流为140 A时,焊缝的熔合区主要由奥氏体和回火马氏体组成,在熔合区与低碳钢母材之间存在一个单一奥氏体柱状晶区;在熔合区与烧结高铬铸铁母材之间,存在一个柱状高铬铸铁区域,该区域的碳化物为粗糙树枝状,沿基体晶界分布。 相似文献
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进行含铁量高的电弧炉烟尘物料的固体废物鉴别时,首先应利用X射线荧光光谱(XRF)确认物料的主要成分及其质量分数、X射线衍射仪(XRD)和矿相显微镜分析物料的主要物相组成等基本理化性质指标;当物料的基本理化性质指标与含铁量高的电弧炉烟尘相同时,再利用矿相显微镜、扫描电子显微镜和激光粒度分析仪分析物料的特征性理化性质指标,包括金属铁和铁氧化物的存在形态、微粒的微观形态和粒度分布,如果至少有一个特征性指标与含铁量高的电弧炉烟尘相同,即可确定物料的产生来源为含铁量高的电弧炉烟尘;最后,根据《固体废物鉴别标准 通则》(GB 34330—2017)得出物料的固体废物鉴别结论。试验研究指出了含铁量高的电弧炉烟尘物料的三大特征性理化性质指标和固体废物鉴别流程,为含铁量高的电弧炉烟尘物料的固体废物鉴别和监管提供参考,对将其堵在国门之外具有重要意义。 相似文献