低合金高性能高速钢中的碳化物及其对刀具切削寿命的影响

研究了Ｗ４Ｍｏ３Ｃｒ４ＶＳｉ低合金高性能高速钢的碳化物数量及成分特点，发现此钢的一次碳化物数量明显少于Ｍ２钢，而二次硬化碳化物中铬含量比Ｍ２钢高。文中对比分析了Ｗ４Ｍｏ３Ｃｒ４ＶＳｉ和Ｍ２钢的的二次硬化碳化物析出能力，并根据一次，二次硬化碳化物对高速钢切削寿命的贡献说明了Ｗ４ＭｏＣｒ４ＶＳｉ钢利用合金成分设计，在大大节约贵重合金元素Ｗ，Ｍｏ的条件下获得与通用高速钢相当的切削寿命的原因。     

W9Mo3Cr4VRE稀土高速工具钢的研制

在高速钢中加入稀土元素有助于净化钢质,改善钢的组织和性能。介绍了通过电渣重熔生产Ｗ９Ｍｏ３Ｃｒ４ＶＲＥ稀土高速工具钢的工艺。     

新型热作模具钢（JM）的研究与应用

５Ｃｒ４Ｗ４ＭｏＶＮｂ钢（ＪＭ）是一种新型加钒、铌的Ｃｒ－Ｗ－Ｍｏ热作模具钢。应用结果表明，该钢具有良好的锻造性能和机械加工性能，用该钢制作的精锻齿模和扳手模的使用寿命比３Ｃｒ２Ｗ８Ｖ钢提高１倍以上。     

3Cr2W8V代用钢的Si,Mn含量与作用

通过比较类似钢种的成分，组织特征，分析论证了在３Ｃｒ２Ｗ８Ｖ代用钢（４Ｃｒ３Ｍｏ２Ｖ型）中加入适量的Ｓｉ，Ｍｎ可提高钢的性能，探讨了Ｓｉ，Ｍｎ在二次硬化热作工具钢中的复合强化机制。     

W9Mo3Cr4V钢的超细化处理

采用不同的工艺参数,对Ｗ９Ｍｏ３Ｃｒ４Ｖ钢进行高温变形,获得了一种超细的再结晶组织。进一步分析了产生这种超细组织的原因和条件,为高合金钢的超细化处理提出了一种有效的方法。     

新型热精锻模具钢3Cr4Mo2NiVNb的研制

新开发的新型热精锻模具钢３Ｃｒ４Ｍｏ２ＮｉＶＮｂ热强性明显高于Ｈ１３，在应用过程中，模具寿命较３Ｃｒ２Ｗ８Ｖ钢高０．５￣２倍。     

六辊轧机中间辊用钢接触疲劳性能研究

采用金相、ＴＥＭ、ＸＲＤ等手段研究了六辊轧机中间辊用５５Ｃｒ５ＮｉＭｏＶ及７０Ｃｒ３Ｍｏ钢的接触疲劳性能。结果表明：５５Ｃｒ５ＮｉＭｏＶ钢的接触疲劳性能明显高于传统的７０Ｃｒ３０Ｍｏ钢。５５Ｃｒ５ＮｉＭｏＶ钢组织中的残 奥氏体量较７０Ｃｒ３Ｍｏ钢接触疲劳过程中,残余奥氏体发生应变诱发马氏体转变,这种应变诱发转变可抑制并阻碍疲劳裂纹的产生和扩展。     

25W3Mo4Cr2V7Co5钢过饱和渗碳的碳化物及性能

研制的２５Ｗ３Ｍｏ４Ｃｒ２ＶＣｏ５高韧高硬高速钢的共晶碳化物尺寸平均为２－４μｍ，最大约为８μｍ；经最佳规范过饱和渗碳后碳化物尺寸平均为４－６μｍ，最大亦仅为１０μｍ。热处理后的硬度可达ＨＲＣ６７－７０，用该钢制造的车刀，其耐用度显著高于Ｗ１８Ｃｒ４Ｖ钢。     

JZF—35复合转毂矫直机矫直调整参数的实践与研究

以复合转毂矫直机矫直高速工具钢Ｗ９Ｍｏ３Ｃｒ４Ｖ为特例，较详细研究了矫直调整参数的计算方法，过程和分布规律。     

无莱氏体高速钢2W－3Mo－4Cr－6V

在本文作者研制的有别于基体钢，低碳高速钢和普通渗碳高速钢的新型无莱氏体高速钢的基础上，又成功地研制成一种高Ｖ无莱氏体高速钢２Ｗ－３Ｍｏ－４Ｃｒ－６Ｖ。该钢经热处理后硬度高于７０ＨＲＣ，６００℃红硬性为６７．５ＨＲＣ。用其制成Ｍ３３挤压丝锥的使用寿命较１８Ｗ－４Ｃｒ－Ｖ丝锥高２倍。     

Analysis of High Temperature Deformed Structure and Dynamic Precipitation in W9Mo3Cr4V Steel

In recent years,high temperature deformationand recrystallization have been commonly studied incarbon and low alloy steels[1— 6] .Ref. [3]and Ref.[6 ]have investigated the behavior of hightemperature deformation and recrystallization inhigh speed steels. Using TEM and SEM,variousdeformed structures and sub- structures,dynamicrecrystallized nuclei and dynamic precipitation inW9Mo3Cr4 V steel were studied.1　 Experimental Procedure1.1　 Sample preparation　　 The material used is a commer…     

Grain Refinement of Nb Steels by Control of Recrystallization during Hot Rolling

Control rolling of Nb-bearing steels is employed to produce the uniform fine-grained product needed to meet the most stringent strength and toughness specifications. To produce such structures consistently requires a thorough understanding of the effects of compositional and process variables on austenite grain refinement at every stage of the hot rolling process. These effects were examined by means of a laboratory simulation of plate rolling. It was found that limiting the reheated grain size to about 100 μm (by lowering the reheat temperature or by adding Ti to the steel) is essential to assure complete recrystallization and refinement of the initial grain structure without an excessive amount of reduction at high temperatures. Because of the slow cooling rate at the slab center, this initial breakdown stage of rolling must be followed by a hold to allow the slab to cool to the lowest temperature at which recrystallization during rolling will be complete. This procedure will assure that the second roughing stage will produce the finest and most uniform recrystallized structure possible. This structure transforms to a very uniform ferrite-pearlite with a grain size of 10 to 15 μm. If, however, the fine recrystallized austenite is further rolled below the recrystallization temperature (control rolled) it will produce flattened austenite grains that transform to ultra-fine ferrite 4 to 6 μm in diameter. The uniformity of the final structure depends critically on the state of the austenite prior to grain flattening. The austenite must be completely recrystallized, since partially recrystallized regions produce duplex ferrite. Two attempts to change the control-rolling temperature range by modifying composition were unsuccessful. Increasing the Nb content from 0.05 to 0.10 to promote higher-temperature precipitation and boundary pinning did not raise the temperature at which grain flattening began. The addition of Ti to a Nb steel to remove soluble nitrogen and thereby prevent formation of NbCN in favor of the lower-temperature NbC did not promote recrystallization to lower temperatures.     

热变形对轴承钢G80T晶粒细化行为的影响

利用Gleeble-3800热模拟变形试验机,对高温轴承钢G80T的动态再结晶行为及相关力学性能进行了研究。通过对该钢在1 050℃下以10s-1的变形速率进行0%~70%的不同形变量的单道次压缩,研究了不同形变量下热变形钢的微观组织结构及硬度。结果表明:当形变量在20%时,无动态再结晶发生;当形变量达到40%时,热变形组织出现了部分的再结晶晶粒;随着形变量的进一步加大,再结晶晶粒数目增多,形变量达到60%后,形变组织形成了平均晶粒尺寸为2.8μm的完全再结晶组织。同时由于形变和晶粒尺寸大幅度细化,钢中的碳化物也随着形变量的增加而逐步减少。通过对压缩应力-应变曲线软化行为的分析,认为该钢的再结晶属于动态再结晶;在1 050℃进行60%的形变可以实现该钢的完全动态再结晶,将平均晶粒尺寸从原始的22μm细化到2.8μm,同时将钢的硬度从820 HV提高到895 HV。研究结果表明,动态再结晶是细化高温轴承钢G80T晶粒尺寸和提高性能的一种有效措施。     

316LN高氮超低碳奥氏体不锈钢的热变形行为和组织演变

试验的316LN钢（/%:0.011C,0.49Si,1.52Mn,0.016P,0.001S,16.65Cr,13.43Ni,2.18Mo,0.153N）为7.2 t铸锭初轧开坯并锻造成的Φ180 mm圆钢。利用Gleeble-3800热模拟试验机研究了316LN钢在应变速率0.1~50 s^-1、1050~1200℃时的热变形行为和组织演变规律,并通过线性回归分析建立了316LN钢的本构方程。结果表明,变形温度升高有利于动态再结晶的形核,并在热变形过程中促进动态再结晶扩展;热变形过程材料常数α为0.0061,应力指数n为5.5436,表观激活能550.512 kJ/mol,动态再结晶晶粒数量随着变形温度的增加而增多,到1 200℃变形时发生了完全的动态再结晶。     

Structure and fatigue properties of 08Kh18N10T steel after equal-channel angular pressing and heating

The structure of corrosion-resistant austenitic 08Kh18N10T steel is studied after equal-channel angular pressing (ECAP), heating, and subsequent cyclic tests. After ECAP, an oriented mainly subgrain structure with a structural element size of 100–250 nm and a high fraction of deformation twins forms in the austenite of the steel, and 42 vol % of lath martensite appears. Dynamic twinning, martensitic transformation, dynamic recovery, and even recrystallization take place in the 08Kh18N10T steel during cyclic deformation in the course of fatigue tests according to the scheme of repeated tension. The fatigue strength increases after ECAP due to the refinement and twinning of an austenite structure and the appearance of martensite. The fatigue limit is maximal after ECAP and heating at 550°C for 20 h due to a high annealing twin density in a predominantly austenitic recrystallized matrix, intense dynamic twinning, and martensitic transformation during cyclic deformation.     

Effects of Static Recrystallization and Precipitation on Mechanical Properties of 00Cr12 Ferritic Stainless Steel

The 00Cr12 ferritic stainless steel samples were isothermally held at different temperatures in the range of 700 °C to 1000 °C to investigate the effect of static recrystallization and precipitation on mechanical properties, such as microhardness, tensile strength, and yield strength. The results show that the formation of the fine recrystallized grain, as well as precipitation, coarsening, and dissolution of the second-phase particles, influences the mechanical properties remarkably. The fine recrystallized grain can provide a positive grain boundary-strengthening effect in the sample under a relatively high holding temperature. Coarsening and dissolution of M₂₃C₆ result in partial depletion of precipitate hardening. In contrast, the size and number density of MX particles are almost constant, regardless of the holding temperature; therefore, it can provide a better precipitation-hardening effect.     

Study of High Temperature Deformation and Recrystallization in W9Mo3Cr4V Steel

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预处理温度对00Cr12Ni10MoTi马氏体不锈钢强度的影响

 研究了预处理温度对00Cr12Ni10MoTi马氏体不锈钢强度的影响。研究结果表明：在较低预处理温度下,通过非扩散α′→γ逆转变形成的奥氏体遗传了原始的锻态组织。而在950℃以上温度预处理则形成再结晶的奥氏体。由于最终750℃固溶处理遗传了预处理组织,因此预处理对钢的强度有明显的影响。材料在低于850℃预处理时最终组织中残余奥氏体量较高,不利于提高强度。850℃预处理出现峰值强度,继续提高预处理温度,强度又下降。由于950℃以上预处理形成再结晶的奥氏体,使得最终热处理后的强度稳定在较低的水平。     

Texture Evaluation of a Bi-Modal Structure During Static Recrystallization of Hot-Deformed Mg-Al-Sn Alloy

In this study, Mg-Al-Sn alloy was hot compressed at 523 K (250 °C) and annealed at 623 K (350 °C) for various times. The initial as-deformed microstructure was partially dynamic recrystallized with strain-induced precipitates on the recrystallized grain boundaries. After annealing at 623 K (350 °C), static recrystallization (SRX) of the bimodal microstructure took place where, at this temperature, no static precipitates formed. The goal of this work was to study the effect of dynamic precipitation on the texture evolution during the SRX process. Progressive texture evolution was studied during annealing by electron backscattered diffraction technique through a microstructure-tracking process. It was found that the grain-coarsening mechanism during the early stage of annealing is not totally controlled by the basal-oriented grains. Also, it was found that the dynamic precipitates may have significant influence in the early texture weakening during annealing of a bimodal structure.     

含铌钢碳氮化物二相粒子在控轧控冷工艺中析出规律

针对含Nb微合金化钢，模拟安钢中板厂现有生产工艺，利用透射电镜技术，研究在试验室条件下，通过对试样进行单道次及多道次金属再结晶区和未再结晶区的控制轧制，探讨控轧控冷工艺对Nb碳氮化物第二相粒子析出规律的影响，并结合安钢轧制工艺现状，提出建议。