Nb 和热处理对 C-Mn-Si 系冷轧双相钢组织和性能的影响

用25 kg真空感应炉冶炼的含Nb双相钢(%:0.19～0.21C、0.7～0.8Si、1.9～2.1Mn、0.02～0.04Nb)和不含Nb双相钢(%:0.17～0.19C、0.4～0.6Si、1.7～1.9Mn),经实验室双辊轧机轧成3.5 mm板,再冷轧至1.0mm和1.36 mm钢板.冷轧板通过盐浴炉加热至740～820℃缓冷至680℃,再以≥150 ℃/s冷至280℃保温240 s空冷.结果表明,随加热温度提高,铁素体-马氏体组织中的马氏体量增加;当加热温度为820℃时C-Mn-Si双相钢抗拉强度可达1 050 MPa,加Nb后由于晶粒进一步细化,820℃加热时,其抗拉强度可达1 200 MPa.     

碳对稀土重轨钢组织和性能的影响

通过真空感应炉模拟实验,结合金相分析和性能测定.研究碳对于稀土重轨钢微观组织、冲击韧性和强度等的影响作用.研究表明,随着碳含量的增加,稀土重轨钢的奥氏体晶粒尺寸和珠光体片层间距逐渐增大,屈服强度和抗拉强度逐渐增大,冲击韧性则逐渐减小.在本实验条件下,将稀土重轨钢的碳含量控制在0.600%～0.650%之间,对于强度的损失并不大,但对于改善冲击韧性具有显著效果.     

热处理对履带用奥氏体-贝氏体钢 38CrMnSi2RE 组织和性能的影响

研究了880～900 ℃奥氏体化,280～340℃盐浴等温淬火对拖拉机履带用铸态低合金奥氏体-贝氏体钢38CrMnSi2RE(%:0.35～0.42C、1.5～2.0Si、1.0～1.5Mn、1.0Cr、0.2RE)力学性能和耐磨性的影响.试验结果表明,38CrMnSi2RE钢最佳热处理工艺为880～900℃奥氏体化,310℃等温60 min.该钢抗拉强度≥1 100 MPa,伸长率=7.9%,HRC硬度值1≥44,冲击值≥88 J/em2.38CrMnSi2RE钢履带板的使用寿命为ZGMn13钢的1.69倍.     

ARB工艺对1060工业纯铝组织和性能的影响

采用ARB技术中两种轧制工艺, 研究变形后1060工业纯铝的显微组织和力学性能变化. 结果显示, 在两种ARB轧制工艺中, 单向轧制工艺的晶粒细化效果明显好于换向轧制. ARB7道次后, 采用单向轧制工艺试样的显微组织由拉长的细小纤维状晶粒组成, 平均晶粒尺寸是470 nm;采用换向轧制工艺试样由等轴状晶粒组成, 平均晶粒尺寸是680 nm. 同时, 单向轧制后, 材料的抗拉强度和显微硬度提高程度大于换向轧制, 但延伸率却不如换向轧制. 分析了ARB过程材料的变形规律和细小晶粒的形成机制.     

等温退火对W6Mo5Cr4V2高速钢碳化物堆积的影响

利用扫描电镜观察了不同退火工艺下钨钼系高速钢中碳化物的堆积状态,并用能谱仪分析了堆积处碳化物类型.结果表明,堆积处的碳化物类型为M6C;高速钢等温退火中的等温温度和保温时间选择不当是造成碳化物堆积的主要原因;对已产生碳化物堆积的钢材,可采用较低温度的二次退火工艺来消除碳化物堆积.     

Reactions of Molybdenum and Tungsten Carbides with Oxygen at High Temperatures

The interaction of Mo₂C, W₂C and WC with O₂ has been measured between 1300 and 2100 K and 10⁻⁴ and 40 mbar O₂. The weight loss of the carbides is very similar to that of Mo or W, respectively. The reason for this is a metallic surface layer produced on the samples by a fast CO reaction. Its thickness is reduced again by the evaporation of volatile oxides. The superimposition of these two reactions finally results in a steady state with a constant layer thickness between 0.1 and 100 μm. The layer growth and steady state conditions can be calculated from literature data for binary systems. The theoretical values are in agreement with experimental results and show similar trends. Formerly Visiting Scientist at the Max-Planck-Institut     

电弧炉钨钼氧化物间接加入合金化生产高速钢

目前 ,生产高速钢基本上都采用钨钼氧化物直接加入炉中进行冶炼[1 ,2 ] ,钨钼氧化物加入量可达 80ｋｇ/ｔ钢。在此范围内 ,各项指标如冶炼时间、电耗、钨钼回收率、钢材理化性能和Ｍｎ/Ｓ比等都与采用铁合金差不多[3～ 5] 。但如果要改变钨钼氧化物的加入量或者要求降低氧化物中的钨钼含量和磷硫含量 ,扩大冶炼钢种的范围 ,直接加入法便无法满足这些要求。为此 ,试验了冶炼中间产品原料钢 ,提出了钨钼氧化物间接加入法工艺。1　间接加入法工艺———原料钢的冶炼1 .1　工艺方案采用钨钼氧化物直接法冶炼时 ,需配置全部炉料 40 %～ 5 0 %的返…     

钨钼钒氧化物矿直接合金化冶炼高速钢的理论及技术

对用白钨矿、氧化钼和V2O5直接合金化冶炼高速钢进行了热力学和动力学的计算和分析。在理论研究的基础上,进行了用白钨矿、氧化钼和V2O5直接合金化冶炼高速钢的工业试验。在工业试验中开发了装入制度、碱度控制、渣量控制等技术。工业试验获得成功,采用白钨矿、氧化钼、V2O5冶炼M2高速钢合金化率达13%,合金元素W、Mo、V的收得率分别达95.25%、98.01%、90.72%;所获得的钢材质量良好。直接合金化工艺较铁合金冶炼M2高速钢成本降低6813.5元/t。     

The Transformation of Carbides during Austenization and Its Effect on the Wear Resistance of High Speed Steel Rolls

The transformation of carbides with austenization time of a high speed steel (HSS) roll material, manufactured by a centrifugal casting method, has been studied. The correlation between wear resistance and the type, morphology, volume fraction, and distribution of the carbides has also been investigated. Microstructural observations, X-ray diffraction (XRD) analysis, hardness measurements, and energy dispersive spectroscopy (EDS) have been used to characterize the carbides. The type and volume fraction of carbides were found to change with austenizing time. During austenization, the transformation of the M₃C carbides can be postulated as M₃C + γ-Fe → M₂C, with much finer nodular and rodlike MC carbides also forming through a solid-state transformation. The M₂C carbide decomposes as M₂C + γ-Fe → MC + M₇C₃ + M₆C. The decomposed carbide substantially maintains a platelike shape until the end of decomposition. The most important finding of this study is that austenization results in changes in the type, morphology, volume fraction, and distribution of carbides and that it can be controlled to produced a homogeneous distribution of hard carbides, resulting in an improvement in the wear resistance of HSS rolls. This finding may be of great use for the industrial production of HSS rolls.     

RE-Ti复合变质对高钒高速钢组织和性能的影响

研究了RE-Ti对高钒高速钢铸态组织、热处理组织和性能的影响.结果表明,变质处理使高钒高速钢共晶碳化物的形貌和分布得到了改善,共晶组织中片层状碳化物变短、变细.热处理后,共晶碳化物大部分变成团球状且分布均匀.变质剂中的合金元素可促进晶粒中或沿晶界均匀分布的非连续状硬质碳化物的生成,从而达到改善组织、提高硬度的作用.并分析了变质剂在高钒高速钢中的作用机理及改善合金性能的机制.     

Effect of Heat Treatment on Microstructure and Properties of High Boron-High Speed Steel

A new type of high boron-high speed steel (HB-HSS) with different boron content was selected for oil quenching at 1050 °C, and different temperature of tempering treatment was chosen. By using optical microscopy, scanning electron microscopy, X-ray diffraction, Rockwell hardness tester, red hard treatment and wear test, the effects of heat treatment on microstructure and properties of HB-HSS were investigated. The experimental results indicate that the quenching microstructure of HB-HSS consists of α-Fe, M₂(B, C), M₇(B, C)₃ and a few of M₂₃(C, B)₆. When the tempering temperature is lower than 500 °C, the shape of carboborides will change from discontinuous sheet to continuous net, and the uniformity in microstructure is improved, and the hardness is not changed during the process. When the tempering temperature is higher than 500 °C, the continuous net of M₂(B, C) is recovered. When the tempering temperature is higher than 600 °C, the microstructure of HB-HSS get thickened because of overheating, and the hardness get significantly reduced. With the increase of tempering temperature, the weight loss of the sample is decreased, and the wear resistance of the sample is increased. When tempering temperature exceeds 500 °C, the weight loss of the sample has an obvious increase and its wear resistance decreases. The wear resistance of the sample decreases after the red-hardness treatment. The wear loss is about 8.4 mg when the boron content is 2.0% and the tempering temperature is 500 °C, which is the best of test samples.     

合理利用我国高钼钨精矿

面对我国许多矿山选矿产出的高钼钨精矿(或次精矿)越来越多的状况,根据不同原料及不同用户需要,提出了合理利用我国高钼钨矿资源的几条途径。     

Effect of Rare Earth on Microstructures and Properties of High Speed Steel With High Carbon Content

The effects of rare earth （RE） on the microstructures and properties of high carbon high speed steel （HCHSS） were investigated. The results show that when suitable RE is added to the HCHSS, the effect of RE on the austenite and eutectic carbides is obvious. The austenite grain and coarse eutectic structure are refined, and flake carbides in the eutectic structures become short and fine. After heat treatment, most of the eutectic carbides are spheroidized and distributed in a uniform manner. The hardness and red hardness of modified HCHSS are slightly increased; impact toughness is greatly increased by 37.81% and reaches 10.17 J/cm^2. The mechanism by which RE improves the structures and properties of HCHSS is also analyzed.     

Effect of RE－Al－N on Structures and Properties of M2 Cast High Speed Steel

M 2highspeedsteel (M 2steel)isamaterialwidelyusedintoolsanddies[1,2 ] .M 2steelischarac terizedbyalongsolidificationrangeandcomplexeu tecticreactions ,whichresultsinsegregationofalloy ingelementsandformationofseveraldifferenttypesofcarbidesduringsolidification[3,4 ] .Forconventionallyprocessedhigh speedsteels ,itisinevitablethatacoarsecarbidenetworkwillbeformedduringsolidifi cation .Coarseprimarycarbidestendtoresultinun evencarbidebandsdistributionafterasubstantialamountofhotprocessing[5] .Ma…