17—4PH马氏体沉淀硬化不锈钢的生产工艺探讨

17—4PH 钢是属於马氏体沉淀硬化不锈钢,它是美国 ARMCO 钢公司在1949年发表的,其特点是强度高,耐蚀性好,易焊接,热处理工艺简单,缺点是延韧性和切削性能差,这种马氏体不锈钢与靠间隙元素碳强化的马氏体钢不同,它除靠马氏体相变外并在它的基体上通过时效处理析出金属间化合物来强化。正因为如此而获得了强度高的优点,但延韧性却差。     

形变热处理工艺对403Nb马氏体耐热钢组织和性能的影响

403Nb是一种马氏体耐热不锈钢,主要用于制作火电机组汽轮机叶片,该钢是在AISI 403不锈钢的基础上,通过添加一定质量分数的Nb和V 发展起来的。通过与传统热处理工艺对比,研究了形变热处理工艺(即高温固溶后在奥氏体亚稳态区变形后空冷)对马氏体耐热钢403Nb的组织和性能的影响。结果表明：形变热处理可以使403Nb钢组织明显细化,马氏体板条宽度由传统热处理的0.3 μm减小到0.1 μm,而且生成大量弥散的纳米级MX碳化物。形变热处理对403Nb钢组织改变的直接结果是可以大幅度提高403Nb钢的屈服强度,在常温拉伸时由传统热处理的800 MPa提高到1 180 MPa,在高温(700 ℃)拉伸时由246.5 MPa提高到341.4 MPa,其屈服强度分别提高了47.55%和38.5%。     

硼微合金化对6Mo超级奥氏体不锈钢微观组织及耐蚀性影响

摘要：综述了6Mo超级奥氏体不锈钢凝固、热加工和热处理阶段的微观组织演化规律,并分析了合金元素对Mo偏析和σ相析出及耐蚀性能的影响规律。结合作者前期工作,重点分析了微合金化元素硼对其凝固阶段Mo偏析、热加工和热处理阶段σ相析出以及耐蚀性能的影响。硼抑制热加工过程中σ相的析出,减小析出相数量和尺寸,有利于热塑性提高;同时还可促使钝化膜表面形成富铬和富Mo氧化物,加速基体表面钝化膜致密化,且减缓晶界处贫Cr和贫Mo区,提高耐蚀性。     

用等离子旋转电极工艺生产高氮钢

为了寻求高效、经济的高氮钢生产工艺,用等离子旋转电极工艺(PREP)生产高氮钢并测试了所生产的几种典型高氮钢的性能。结果表明,氮可显著地提高奥氏体不锈钢1．4301的室温及高温强度;氮可以提高马氏体不锈钢的强度。为保证高氮马氏体不锈钢的淬透性,应根据氮含量适当降低其碳含量或提高铬含量。对于铬含量为17％的马氏体不锈钢1．4122,其碳和氮的总含量不应超过0．65％;当氮含量达到0．24％时,铁素体不锈钢1．4016转变成为马氏体钢,其强度高于碳和氮的总含量与其相当的普通马氏体不锈钢1．4122。     

易切削高硬度马氏体不锈钢研究

采用非真空感应炉＋电渣重溶冶炼工艺，改善了硫化物分布情况，提高了材料热加工塑性，摸索了合理可行的生产加工工艺和热处理工艺，开发了具有易切削，高硬度，耐腐蚀特性的马氏体不锈钢。     

在Φ825mm轧机生产SuS630Φ100mm钢材生产工艺的研究

马氏体沉淀硬化不锈钢的热加工温度范围较窄,轧制成形比较困难,本文介绍了马氏体沉淀硬化不锈钢SuS630在Φ825mm初轧机上和Φ825mm单机座精轧机上生产Φ100mm钢材的生产工艺;较详细地介绍了该种钢的加热工艺、压下制、轧制方式、轧制温度及在轧机上所采用的孔型系统,同时对成材后的热处理工艺也作了介绍。通过制订的工艺在生产中的实践,证明了该工艺是可行的;钢坯的成材率指标、钢材的尺寸精度、表面质量、组织性能均达到了较好的水平。     

不锈钢概论（9）

3马氏体不锈钢的发展和性能特点马氏体不锈钢是一类可通过热处理（淬火、回火）①对其性能进行调整的不锈钢。按它们的成分特点可分为马氏体铬不锈钢（Fe—Cr—C马氏体不锈钢）和马氏体铬镍不锈钢（Fe—Cr—Ni马氏体不锈钢）。     

新型低铬镍高硅双相不锈钢的组织及其腐蚀行为研究

设计了新型低铬镍高硅双相不锈钢的组织及其化学成分，采用金相显微镜、Ｘ射线衍射、扫描电镜和多种腐蚀方法研究了本试验钢的组织及其腐蚀行为。试验结果表明这种钢在高温浓硫酸介质中具有良好的耐蚀性、抗晶间腐蚀、点蚀、电化学腐蚀性能以及高的塑韧性。     

17-4PH钢的合金化及强化机制浅析

本文从17 -4PH沉淀硬化不锈钢的化学成分设计、热加工和热处理、金相组织及其性能进行了分析,阐述了17 - 4PH钢的强化机制及其影响因素.结果表明,17 - 4PH钢的强化机制特点是通过钢中各元素有效合金化,通过热处理手段使其产生热力学和动力学反应达到强化作用,使钢获得较高的强度和韧性.     

国内外高氮马氏体不锈轴承钢研究现状与发展

 高碳铬不锈钢是应用最为广泛的不锈轴承钢,其具有较高的硬度和一定的耐蚀性,然而较高的碳、铬质量分数导致粗大碳化物的出现,轴承钢的疲劳和耐蚀性能将受到损害。相比之下,钢中添加氮元素能够减少粗大共晶碳化物的数量,同时析出大量细小的氮化物及碳氮化物,氮代碳既强化基体又改善耐蚀性,从而获得高强度与良好耐蚀性。介绍了含氮轴承钢及含氮马氏体轴承钢的发展历程,分析了不锈轴承钢中氮元素对组织结构、力学性能和耐蚀性能的作用机理;介绍国内外含氮轴承钢的研究现状并指出了含氮轴承钢研究的不足,需要在氮溶解模型、氮对组织演变及耐蚀机制等方面进行基础理论研究,同时不断研发不同系列的含氮马氏体轴承钢。     

双相不锈钢成分、性能及析出相分析

叙述了常用的超级双相不锈钢的成分、耐蚀性和应用,分析了不同种析出相、有害相、点蚀当量值(PRE)及焊接对双相不锈钢组织和性能的影响,得出通过控制合金化成分,调整点蚀当量值,编制合理的热处理工艺,严格控制有害相析出,使两相比含量比值接近1,可获得良好耐蚀性、高强度和耐磨性的双相不锈钢。     

High density sintering of duplex stainless steels

Abstract

Duplex stainless steels prepared from mixes of elemental powders with martensitic 410L steel have been shown to possess stable dual phase microstructures. Following heat treatment, the steels possess good mechanical properties. The addition of boron as a sintering aid reduces compressibility but promotes densification through transient liquid phase sintering; its effect on corrosion resistance is particularly favourable.     

Development of nitrogen-alloyed stainless steel sheet products in Baosteel

Nitrogen plays a vitally important role for improving properties for stainless steels in many aspects.In this paper,the physical metallurgy behavior and the beneficial effects of nitrogen on corrosion resistance and other mechanical properties of stainless steels were summarised.Based on nitrogen alloying,various stainless steel products,such as austenitic,duplex and martensitic staniless steels were developed with enhanced properties,such as corrosion resistance,mechanical strength and weldability,among other things.     

304与301B奥氏体不锈钢在线固溶热处理工艺研究

通过双道次热压缩和热轧试验研究了在线固溶热处理工艺对304和301B奥氏体不锈钢组织和性能的影响,提高终了压缩温度、冷却速度,降低卷取温度,可以改善奥氏体不锈钢微观组织,减少碳化物析出,提高抗晶间腐蚀能力和力学性能.将该工艺应用于工业生产的304奥氏体不锈钢热轧卷板,测试结果表明304各项性能得到改善,冷轧前退火工序可被在线固溶取代.     

锰对高氮超级马氏体不锈钢组织与性能的影响

 为了进一步提高超级马氏体不锈钢的强塑性能和优良耐腐蚀能力,在实验室条件下研发制备了氮质量分数为0.35%、锰质量分数分别为0.4%和2.0%的2种新型超级马氏体不锈钢试料,并采用淬火-配分的工艺对其进行处理;借助万能试验机、光学显微镜、扫描电镜、透射电镜和电子背散射衍射等方法对试验钢的微观组织和力学性能进行表征测试。研究表明,2种试验钢经一定制度的淬火-配分处理后,力学性能相比典型超级马氏体不锈钢均有显著提升;同时发现锰元素含量对试验钢强塑性能影响显著,锰质量分数由0.4%提升到2.0%时,试验钢的抗拉强度和伸长率分别由1 690 MPa、15.2%改变为1 215 MPa、35.1%,均突破了传统超级马氏体不锈钢的强塑性能指标;分析认为强塑性显著提升的原因是氮-锰元素协同作用使淬火-配分后残余奥氏体含量增加显著,并伴随纳米级逆变奥氏体和氮化物析出所致。     

核电站设备制造中双相不锈钢的应用

奥氏体-铁素体双相不锈钢中稳定存在奥氏体相和铁素体相,该钢具有较高的机械性能和优异的耐点蚀、晶间腐蚀和应力腐蚀性能,在核电站设备制备中被广泛应用。一般双相不锈钢铸件中铁素体相的体积分数≤20%,服役温度≤425℃,双相不锈钢锻件中铁素体相约占50%,服役温度≤250℃。文中介绍了核电站设备中应用的双相不锈钢铸、锻件的化学成分、制造和焊接工艺要求及组织和性能。     

非API 13Cr系马氏体不锈钢油套管的发展现状

API(美国石油协会)13Cr油套管具有良好的耐CO₂腐蚀性,但随新油田的开发,要求油套管具有优良的抗H₂S、CO₂高温耐蚀性。文中分析了国内外非API 13Cr马氏体不锈钢油套管(Cr13-Ni5-Mo,Cr13-Ni5-Mo2,Cr15-Ni6-Mo2-Cu等)的发展现状,叙述了相关生产厂家油套管的化学成分、力学性能和耐蚀性。     

Sensitization Behaviour of Manganese‐Alloyed Austenitic Stainless Steels

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.     

经济型双相不锈钢的研发进展

 经济型双相不锈钢是一种高性能低成本的氮合金化不锈钢新材料,具有典型的铁素体-奥氏体双相组织。利用氮取代镍元素的奥氏体化作用,降低成本的同时获得优良的力学性能和耐腐蚀性能。介绍了经济型双相不锈钢的发展历史,重点讨论了合金元素和热处理对相变、力学性能和耐腐蚀性能的影响规律,并与304和316进行对比;同时,分析了经济型双相不锈钢焊接性能和焊接工艺的研究进展。经济型双相不锈钢S32101、S32003、S32202等,已用于核电、桥梁、建筑、热交换器等行业,取代传统奥氏体不锈钢AISI 304和316。由于经济型双相不锈钢具有高强度和优良耐蚀性,同时镍、钼等贵金属的含量都较低,已成为未来不锈钢发展的方向之一。     

Novel Development of an NbC-Containing Powder-Metallurgical Martensitic Steel with Outstanding Tribocorrosion Resistance

The development of NbC-containing martensitic stainless steels has made it possible to unite the properties of high corrosion resistance and wear resistance. If NbC is used as a hard phase instead of chromium carbide, the abrasive wear resistance of the steels is increased due to the greater hardness of NbC. The solubility of chromium in NbC is low. For this reason, chromium is fully available to form a passive surface layer to increase the corrosion resistance. In the steel melt, niobium leads to the formation of primary NbC, which grows very rapidly. Atomization of PM steels leads to the formation of coarse primary hard phases that clog the nozzle. Therefore, until now, steels with NbC as a hard phase are produced using the PM route with so-called diffusion alloying; however, this production route is very complex and expensive. Herein, a novel Nb-rich MC-containing wear- and corrosion-resistant steel that is produced using the usual PM route is presented. This steel consists of a martensitic matrix with evenly dispersed Nb-rich MC having a volume of 2.5%. Due to the high hardness (>750 HV30) in combination with high resistance to pitting corrosion, the steel exhibits outstanding tribocorrosion resistance in 0.9% NaCl solution.