钢热处理的新工艺

钢经热处理后保存残余奥氏体可以改善钢件的塑性和韧性。在20世纪,我们在热处理中应用奥氏体热稳定化,有效地减小淬火（高速钢回火）时钢件的畸变。本文介绍Speer等近年来发展的钢热处理新工艺-淬火和分配（Q＆P）处理,即含Si或Al的Q—P钢经淬火至Ms—Mf间一定的温度（QT）后,再在一定温度（PT,在淬火温度或者高于Ms）停留,使碳由马氏体扩散（分配）至残余奥氏体,使其稳定化．增加最后淬至室温的奥氏体含量,改善钢件的强、韧混合性质。示例说明,钢经Q—P处理后显示良好的力学性质。实验表明,Q—P热力学模型“限制条件碳准平衡”（CPE,CCE）的限制假设奈件常不存在。认为：在Q—P处理,尤其在较高温度、作较长时间分配处理时,宜以稳态平衡为理论基准,并计算各类可能相变的△G值,以预测可能发生的相变,包括碳化物的析出,γ→α,以及M（α）→γ。碳原子可能按扩散动力学在马氏体和奥氏体两相间分配。以Q—P处理为基础,本文作者提出淬火-分配-回火（Q—P—T）工艺,钢件局域的渗碳,以及高强度钢经碳分配等热处理新工艺。     

Effect of High-Temperature Thermomechanical Treatment on the Brittle Fracture of Low-Carbon Steel

The effect of high-temperature thermomechanical treatment (HTMT) on the brittleness connected with deformation-induced aging and on the reversible temper brittleness of a low-carbon tube steel with a ferrite–bainite structure has been studied. When conducting an HTMT of a low-alloy steel, changes should be taken into account in the amount of ferrite in its structure and relationships between the volume fractions of the lath and the acicular bainite. It has been established that steel subjected to HTMT undergoes transcrystalline embrittlement upon deformation aging. At the same time, HTMT, which suppresses intercrystalline fracture, leads to a weakening of the development of reversible temper brittleness.     

The Influence of Thermomechanical Treatment of TRIP Steel on its Final Microstructure

Higher demands are currently being made on material properties and their combinations, for example, high strength steel with good cold formability. With increasing strength, material formability generally worsens, but with some kinds of steels, for example, with TRIP steel, it is possible to obtain an excellent combination of strength and ductility. However, these materials are interesting not only for use as sheets but also for other applications. Semi-products with thin walls represent the best way of further extending TRIP steels into the bulk forming area. This trend supposes that suitable technological conditions will be found and the process for a chosen production procedure will be optimized. The model optimization of the process for TMT with incremental deformations was experimentally carried out on a thermomechanical simulating machine. Microstructures obtained by the model treatment were analyzed by means of optical and electron microscopy.     

Effect of Thermomechanical Treatment on the Microstructure and Mechanical Properties of an IF Steel

This study focused on thermomechanical treatment of an interstitial-free (IF) steel. As-received IF steel underwent cold reduction of 80% followed by subcritical annealing at 680 °C for 10, 20, 30, and 40 min. These cold-worked and annealed samples were characterized using optical microscopy and scanning electron microscopy (SEM). Mechanical properties such as hardness and tensile strength were determined. Fracture surface was studied using SEM. On the basis of resulting mechanical properties and fractographic study, it was concluded that employing annealing time between 20 and 30 min at 680 °C imparts the desired combination of strength and ductility required for deep-drawing applications in automotive industry.     

固溶处理对0Cr16Ni16钢形变热处理后力学性能的影响

本文阐述了固溶处理机制,且制定了0Cr16Ni16钢形变热处理后的固溶处理工艺,通过试验研究了固溶处理工艺对0Cr16Ni16钢形变热处理后力学性能的影响。研究表明试样形变后进行固溶处理强度有所提高而塑性变差;且在750~900℃范围内,强度随着固溶温度的升高而降低,塑性随着固溶温度的升高而增大。     

Structural and Textural States of Steel 06G2MB Strips After Controlled Thermomechanical Treatment

Metal Science and Heat Treatment - Orientation microscopy (EBSD) is used to study structural and textural states through the thickness of pipe steel strips after a controlled thermomechanical...     

数控机床用PEMFC热处理不锈钢双极板的热机械分析

在试验基础上,分析了不锈钢与石墨接触电阻在不同热处理温度下随热处理时间的变化关系,并建立了质子交换膜燃料电池热处理不锈钢双极板的热机械模型.结果表明:在同一温度下,不锈钢与石墨接触电阻随热处理时间的变化而变化;800℃的高温热处理的接触电阻比900℃的高温热处理的接触电阻明显低得多.热处理不锈钢双极板的最大等效应力和位移都足够小,这对于质子交换膜燃料电池十分重要,必须使其足够小才能使双极板准确分离阳极和阴极的氢气和氧气.     

形变热处理对低碳微合金钢焊接接头组织与性能的影响

针对低碳微合金钢焊接接头存在的组织不均匀,晶粒粗大,硬度上升、韧性下降,力学性能变差,并产生焊接残余应力等,采用形变热处理技术,通过对焊缝在二相区温度下的碾压处理,使其晶粒明显细化,硬度下降,屈强比减小,残余应力消除,焊缝性能得到了优化.     

双晶直探头对船用铸钢件的超声波检测

介绍用纵波双晶直探头对船用铸钢件机加工面进行超声检测的方法,以保证工件精加工后无外露缺陷,从而满足工件的技术要求。文章引进蜂窝状缺陷的概念,侧重于三种蜂窝状缺陷(气孔型、缩孔型和夹渣型)的超声波反射波型特征的分析。实践证明,所述分析方法有利于对铸钢件内部缺陷评定;结合对缺陷反射波的动态波形观察有助于较快速进行缺陷定位、定量和定性;采用2～4MHz、焦距15～20mm双晶直探头,3mm孔灵敏度,对船用铸钢件粗加工面进行超声检测是确保精加工后缺陷不外露的较好的检测技术。     

热处理对双杠用30MnSiPC钢力学性能的影响

以30 MnSiPC钢为对象,研究淬火温度和回火温度等热处理工艺条件对其力学性能的影响。结果表明,淬火温度为920~960℃,回火温度为400℃左右时,30MnSiPC钢的综合性能最佳。     

Cr-Ni-Mo铸造热作模具钢热机械疲劳行为

研究了新型Cr—Ni—Mo铸造热作模具钢在应力控制下的热机械疲劳寿命、应力应变响应以及疲劳断裂特征。试验中发现，在相同的应力幅下，同相热机械疲劳寿命低于上限温度的等温疲劳寿命。疲劳过程中热作模具钢发生了循环软化和沿着拉伸方向的循环蠕变，热作模具钢的热机械疲劳裂纹往往穿晶萌生，沿晶扩展。     

微合金化低碳贝氏体型非调质钢的控轧控冷

在热模拟试验机上研究了控轧控冷工艺对微合金化低碳贝氏体型非调质钢组织性能的影响，并探讨了贝氏体转变机制问题。结果表明．控轧控冷代替常规轧后回火工艺的途径是可行的，同时有力地支持了粒状贝氏体的扩散型长大学说。     

汽车转向节形变热处理

研究了汽车转向节锻后余热淬火工艺对钢的组织和性能的影响。结果表明，锻造余热淬火工艺对汽车转向节质量有明显改善。余热淬火可以保留变形造成的位错增殖和晶粒细化，从而使材料具有高的强度和韧性：     

形变热处理的强化机理与应用前景

本文结合探讨形变热处理的强化机理,系统分析了形变热处理的常用方法及效果,展望了形变热处理在钢材生产上和机械工业中的应用前景。     

Heat and Thermomechanical Treatment of Concentration-Inhomogeneous Trip Steels

Metal Science and Heat Treatment -     

Effect of Initial Structure on the Deformability and Properties of Steel Subjected to Cold Rolling During Preliminary Thermomechanical Treatment

Results of a study of the effect of the initial structure (granular and lamellar pearlite) of medium-carbon alloy steel 45KhN2MFA-Sh used for the production of torsion shafts on its deformability and hardenability in the process of preliminary thermomechanical treatment (PTMT) involving cold longitudinal rolling in dead rollers are presented. The metal with an initial structure of lamellar pearlite is shown to be more advantageous with respect to the hardening intensity during the rolling and the combination of mechanical properties after the PTMT.     

Preliminary Thermomechanical Treatment of Steel 45KhN2MFA-Sh with the Use of Cold Lengthwise Rolling in Dead Rollers

The effect of modes of preliminary thermomechanical treatment (PTMT) of steel 45KhN2MFA-Sh on its structure and mechanical properties is investigated. It is shown that PTMT with the use of cold lengthwise rolling is an effective method for treating long cylindrical step parts like torsion shafts from high-strength steel 45KhN2MFA.     

CRONIDUR30高氮不锈钢的热处理工艺及组织和性能

CRONIDUR30钢是一种新型高氮、高韧性和高强度马氏体不锈轴承用钢。研究用高氮CRONIDUR30不锈钢的主要成分为0.316%C、14.89%Cr、0.986%Mo、0.425%Mn、0.697%Si、0.207%Ni和0.435%N(质量分数)。对14mm×5mm的CRONIDUR30钢试样进行了1010℃、1020℃、1030℃、1040℃和1050℃油淬、-150℃深冷处理和-85℃冷处理以及160℃、180℃、200℃、250℃、300℃、350℃、400℃、450℃、500℃、600℃回火,检测了经不同工艺热处理的钢的硬度和显微组织。结果表明:经1025℃油淬、-85℃冷处理和470℃回火的CRONIDUR30钢的硬度高于60HRC,组织为回火马氏体、细小均匀的氮化物和碳化物及小于5%的残留奥氏体,能满足高端轴承的性能要求。     

Structure and Properties of Steel 40Kh2N2MA After Thermomechanical Treatment with Martensitic-Bainitic Transformation of Austenite

Metal Science and Heat Treatment - Special features of structure formation in steel 40Kh2N2MA are studied after a high-temperature thermomechanical treatment with martensitic-bainitic...