低碳马氏体不锈钢0Cr16Ni5Mo的研制

介绍了宝钢低碳马氏体不锈钢0Cr16Ni5Mo的研制过程。为了获得满足水电设备制造要求的0Cr16Ni5Mo,通过分析主要元素的作用,设计了化学成分;通过软件计算,制定了轧制工艺;通过实验室炼钢、轧制和热处理,确认了材料的性能能够达到要求及加工工艺可行。工业试生产证明,宝钢开发的0Cr16Ni5Mo热加工性良好,力学性能能够达到国内外同类产品的水平。     

04Cr13Ni5Mo超级马氏体不锈钢焊接性能研究

模拟了04Cr13Ni5Mo超级马氏体不锈钢不同焊接热循环条件下热影响区组织,进行了焊条电弧焊接及焊后热处理试验,分析了焊接热模拟试样及焊条电弧焊接头的微观组织、力学性能.焊接热模拟试验结果表明,模拟热影响区的组织主要为低碳板条马氏体,其硬度较母材有较大提高,冲击韧性有所下降;模拟单道焊或多道焊时,不同的冷却速度及层间热处理对模拟热影响区的硬度及冲击韧性影响不大,600℃焊后回火热处理可以明显软化模拟热影响区组织,并让其冲击韧性恢复到较高水平.焊条电弧焊接结果表明,采用04Cr13Ni5MoRe型焊条及配套的焊后热处理工艺,可以获得良好综合力学性能的焊接接头.     

氮含量对0Cr16Ni5Mo马氏体不锈钢高温热变形行为影响

采用Gleeble3800试验机对三种不同N含量的0Cr16Ni5Mo马氏体不锈钢进行等温热压缩实验.通过对真应变-应力曲线及压缩后变形组织的观察,发现相同热变形条件下,N含量的增加提高了试验钢的流变应力,抑制了再结晶晶粒长大.采用Zener-Hollomon参数,以流变应力方程为基础,构建三种本构模型.通过观察拟合应力值与实验值的离散性,确定双曲正弦模型更适用于本试验钢的本构方程计算,优化此计算模型,获得了三种试验钢的本构方程.     

Formability of low-interstitial 18 pct Cr-2 pct Mo ferritic stainless steel

Because of its excellent corrosion resistance, low-interstitial 18 pct Cr-2 pct Mo ferritic stainless steel is being considered for a wide range of applications, many of which involve the forming of sheet. The present investigation was undertaken to examine the effects of rolling schedule on the formability of titanium-stabilized 18 pct Cr-2 pct Mo ferritic stainless steel sheet. Formability and texture development were evaluated by utilizing 1) plastic strain ratios and work-hardening exponents derived from tensile tests; 2) Swift and Olsen cup tests; and 3) X-ray pole figure analysis. Increasing the degree of cold reduction from 70 pct to 92 pct prior to the final recrystallization anneal led to substantial increases in deep drawability through changes in the recrystallization texture. Schedules of two-step cold rolling with an intervening recrystallization anneal, leading to increased total cold reduction, produced significantly higher plastic strain ratios than those produced by the one-step schedules. The crystallographic textures of the sheets were determined and correlated with the observedr values. This paper is based on a presentation made at a symposium on “New Developments in Ferritic and Duplex Stainless Steels,” held at the Fall Meeting in Cleveland, Ohio, on October 19, 1972, under the sponsorship of the Corrosion Resistant Metals Committee on TMS-IMD and the Corrosion and Oxidation Activity of the ASM.     

The microstructural influence of a 2 wt pct Mo addition to a Ti-1.5 wt pct Ni alloy

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Cr32Ni7Mo3N特级双相不锈钢的空蚀行为

利用磁致伸缩空蚀试验机对Cr32Ni7Mo3N特级双相不锈钢在蒸馏水和人工海水中进行了空蚀实验,并采用扫描电镜跟踪观察了经不同时间段空蚀后试样的形貌.通过测量失重绘制了材料的累积失重量和失重率曲线.经电化学工作站测量了材料在静态与空蚀条件下的极化曲线和腐蚀电位变化.对比分析了Cr32Ni7Mo3N与SAF2205双相不锈钢在人工海水的抗空蚀能力.结果表明：Cr32Ni7Mo3N特级双相不锈钢空蚀破坏首先在铁素体薄弱区以及铁素体和奥氏体相界发生,并向铁素体内扩展,铁素体发生解离断裂脱落;奥氏体随着空蚀的进行,滑移线增多,显微硬度值增加,且人工海水中奥氏体显微硬度值比在蒸馏水中的高;铁素体大面积破坏后,奥氏体才失稳产生延性断裂脱落,奥氏体的存在延缓了破坏在整个材料表面上的扩展.空蚀与腐蚀交互影响导致材料在人工海水中加速破坏.Cr32Ni7Mo3N特级双相不锈钢在人工海水中的抗空蚀能力优于SAF2205双相不锈钢.     

Simulation of effect of Nb and V on precipitated phases in 1Cr16Co5Ni2Mo1WVNbN steel

Thermo- Calc software was used to simulate the equilibrium precipitates in the 1Cr16Co5Ni2Mo1WVNbN steel at 650??, and the effect of Nb and V contents on precipitated phases in the steel was investigated. The calculation results show that the main equilibrium precipitates in steel are Laves phase, M23C6, MX and Z phase. With the increase of Nb content, the precipitation of MX phase increases significantly, while the amount of M23C6 carbids decreases, Laves phase increases slightly, the precipitation of Z phase decreases slightly. With the increase of V content, the precipitation of MX phase increases slowly, the amount of M23C6 carbides reduces slightly. There is no V element contained in Laves phase, and the increase of V content has little effect on the precipitation of Laves phase, precipitation of Z phase decreases slightly. The Nb and V contents have little effect on the precipitation temperature of M23C6, MX and Laves phase, and the starting precipitation temperature of Z phase decreases with the increase of Nb content, but increases with the increase of V content.     

00Cr25Ni22Mo2N奥氏体不锈钢的高温氧化行为

采用静态增重法研究了00Cr25Ni22Mo2N奥氏体不锈钢在不同温度下的循环氧化动力学曲线.结果表明,00Cr25Ni22Mo2N不锈钢在700℃时的氧化动力学曲线是一条平行于时间轴的直线,这说明其在该温度下氧化反应非常微弱;在800和900℃时的氧化动力学曲线遵循抛物线氧化规律,具有良好的抗氧化性能.利用扫描电镜、能谱分析和X射线衍射对氧化膜的表面形貌、截面形貌和相组成进行研究,发现该钢在3个温度下都生成了致密和黏附性好的保护性氧化膜,700℃生成的氧化膜主要由Cr2O3和Fe2O3组成,氧化膜很薄;800℃生成的氧化膜由Cr2O3、Fe2O3和少量的NiCr2O4、FeCr2O4组成,氧化膜厚度增加;900℃生成的氧化膜由Cr2O3、Fe2O3和NiCr2O4组成,氧化膜厚度进一步增加.认为氧化膜组成和结构是00Cr25Ni22Mo2N不锈钢具有良好抗高温氧化性能的重要原因.     

The effect of environment on high-temperature hold time fatigue behavior of annealed 2.25 pct Cr 1 pct Mo steel

Total strain control fatigue tests with a 120-second hold period at either peak compressive or tensile strain were conducted on annealed 2.25 pct Cr 1 pct Mo steel. Tests were performed at the total strain range of 1.0 pct at 500 °C or 600 °C in air, 1.3 Pa (10⁻² torr) or 1.3 × 10⁻³ Pa (10⁻⁵ torr) vacuum. The nature of the hold and the environment affect fatigue life and surface crack patterns. A compressive hold is more deleterious than a tensile hold in high-temperature air, while the reverse is true in environments in which oxidation is limited. Observations of cracks at the surface and in cross section indicate that an oxidation-fatigue interaction accounts for the damaging effect of a compressive hold in air tests. In vacuum tests, creep damage has the opportunity to accumulate and causes the tension hold to exhibit the shortest fatigue lifetime.     

双相不锈钢00Cr25Ni6Mo2N热穿孔工艺的研究

通过对双相不锈钢管00Cr25Ni6Mo2N的加热温度与临界变形量关系的试验,加热温度与双相比关系的试验,双相不锈钢热扭转试验,以及通过大量的热穿孔试验及分析研究得出该钢种最佳的热穿孔加工工艺。     

超级奥氏体不锈钢00Cr20Ni25Mo6N0.15的时效析出相研究

以超级奥氏体不锈钢00Cr20Ni25Mo6N0.15为研究对象,采用金相显微镜、扫描电镜等手段分析了在650℃和980℃时效温度不同保温时间条件下对其组织和性能的影响.结果表明:在650℃温度时效时,随着时效时间的延长,晶界处有少量σ相出现,力学性能没有发生明显变化;在980℃温度时效,当时效时间10 h时,晶界有大量的链状σ相出现,材料的强度显著升高,塑性及韧性明显降低.     

Influence of nitrogen-alloying on the tempering properties of the martensitic stainless steel 00Cr13Ni4Mo

The mechanical and corrosive properties of 00Cr13Ni4Mo(S13-4N) were tested and compared with those of 00Cr13Ni6Mo(S13-6).The effects of nitrogen on the properties of the steels were analyzed.The results of the tensile and corrosion tests show the strength,the ductility,and the pitting corrosion resistance of S13-4N are higher,lower and poorer than those of S13-6 respectively,when tempered at a temperature below 550℃and vice versa when the tempering temperature is higher than 550℃.The results of the X-ray diffraction(XRD) and the electron backscattered diffraction (EBSD) analyses reveal that inversed austenite appears at 550℃and the amount of it peaks at 600℃with the best ductility.And the total amount of the inversed austenite in S13-6 is more than that in S13-4N in different forms. Nitrogen performs better in terms of stabilizing inversed austenite while nickel is more favorable for forming inversed austenite,the amount and stability of which affect the ductility remarkably.The reason for the embrittlement of S13-4N at 450℃can be the result of carbide and nitride precipitating at grain boundaries.     

高铬铁素体不锈钢00Cr26Ni6Mo4CuTi的脆性相研究

由于高铬铁素体不锈钢的脆性问题十分突出,在实验室进行了00Cr26Ni6Mo4CuTi钢的固溶、时效试验,研究了加热温度及保温时间对钢中脆性相的影响,找出00Cr26Ni6Mo4CuTi钢脆性相的析出规律,分析了脆性相对钢组织与性能的影响。结果表明:在1 010~1 030℃采用快冷固溶,经过550℃×(3~4)h时效,可使材料的强度、塑性和韧性达到最优。     

Dimensional anisotropy in 18 pct Ni maraging steel

Annealing after hot rolling or extrusion produces anisotropic shape changes in 18 pct Ni maraging steel. It has been observed that the material contracts along the longitudinal direction but expands perpendicular to it. This peculiar behavior has been studied in situ by means of a dilatometer. The dimensional anisotropy (DA) was found to decrease with an increase in the annealing temperature. The metallographic investigations have led to the conclusion that DA is related to the presence of banding in the material.     

Influence of cerium on hot workability of 00Cr25Ni7Mo4N super duplex stainless steel

The effect of Ce on hot workability of 00Cr25Ni7Mo4N steel melted in vacuum induction furnace was studied by Gleeble thermal simulation machine and scanning electron microscopy(SEM).The results showed that ductility of the steel with Ce addition was increased significantly because of increasing content of austenite,segregation of Ce at grain boundaries and modification of inclusion.The optimum range of Ce content in the steel was 0.030 wt.%-0.047 wt.%,and the optimum value was about 0.047 wt.%.The effect of...     

0Cr18Ni9不锈钢中非金属夹杂物来源

为了研究不锈钢连铸坯中非金属夹杂物的主要类型及其主要来源,用扫描电镜分析了0Cr18Ni9不锈钢连铸坯中的夹杂物成成,并分别在AOD渣、大包渣及中间包渣中加入示踪剂进行了三次示踪实验.实验结果表明,0Cr18Ni9不锈钢连铸坯中的非金属夹杂物主要为CaO-SiO₂-Al₂O₃-MgO系夹杂物,其次为MgO-Al₂O₃类尖晶石和硫化物;非金属夹杂物的主要来源是AOD还原期的还原产物、脱硫产物和出钢时混入钢水中的AOD渣滴;AOD出钢后,大包顶渣、中间包覆盖剂和结晶器保护渣不会对钢液造成明显污染.     

Fatigue crack growth in a type 316 stainless steel and a 20 pet Cr/25 pet Ni/Nb stainless steel at elevated temperature

Fatigue failure in metals and alloys occurs by the nucleation and controlled propagation of a surface crack. At ambient temperature propagation is transgranular and is controlled, to a large extent, by continuum plasticity effects at the crack tip. At elevated temperatures this simple process might be affected by oxidation and the tendency towards intergranular propagation. The elevated temperature fatigue crack propagation behavior of a 20/25/Nb stainless steel and a type 316 stainless steel is studied by optical measurement of the crack growth rate of artificially-induced notches under conditions where gross plastic straining is present in the bulk of the material. Tests conducted at ambient temperature are included for comparison with elevated temperature behavior. By reference to fatigue life data for smooth unnotched specimens, tested under identical conditions to the crack growth tests, an attempt is made to rationalize the roles of crack initiation and propagation in the fatigue process and indicate the relevance of crack growth data in predicting fatigue life data.     

Fatigue crack growth in a type 316 stainless steel and a 20 pet Cr/25 pet Ni/Nb stainless steel at elevated temperature

Metallurgical and Materials Transactions A - Fatigue failure in metals and alloys occurs by the nucleation and controlled propagation of a surface crack. At ambient temperature propagation is...     

回火对00Cr15Ni6Mo2高强马氏体不锈钢组织和性能的影响

研究了一种高强马氏体不锈钢00Cr15Ni6Mo2在回火过程中的逆变奥氏体的体积分数变化及其对力学性能的影响.结果表明,在550 ～750℃之间回火,当回火温度达到670℃时,逆变奥氏体的体积分数达到峰值39％,该钢在670℃回火时的HV硬度为280,夏比V缺口冲击吸收能为187.5 J,也分别达到峰值.沿马氏体板条析出的逆变奥氏体,对提高该钢回火条件下低温冲击韧性具有重要作用.