共查询到18条相似文献,搜索用时 93 毫秒
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热处理工艺对高速钢轧辊组织和性能的影响 总被引:2,自引:0,他引:2
研究了淬火温度、冷却方式、回火温度和回火次数对高速钢轧辊组织和性能的影响.结果表明,油冷条件下,淬火温度低于1050℃,随着温度升高,硬度升高,超过1100℃,硬度反而降低.盐浴冷却(盐冷)和空冷条件下,淬火温度对硬度影响结果相似,但获得最高硬度的淬火温度高于油冷时的淬火温度.回火温度低于350℃,高速钢硬度变化不明显,超过475℃,随回火温度升高,硬度升高,并在525℃达到最高值,继续提高回火温度,硬度降低.二次回火后硬度变化不大,三次回火后,硬度反而降低.空冷高速钢轧辊,淬透性差;油冷高速钢轧辊易出现裂纹;盐冷高速钢轧辊,具有优良的淬透性,不易出现裂纹,辊面硬度高,硬度均匀性好,耐磨性好 相似文献
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RE-Mg-Ti变质对铸造高速钢组织和性能的影响 总被引:4,自引:0,他引:4
用RE-Mg-Ti对低碳铸造高速钢(6W6Mo5Cr4V)模具进行变质处理,消除了钢中网状共晶碳化物,并细化了基体组织,还可减轻W、Mo元素偏析,变质处理后,高速钢硬度、红硬性和强度变化不大,断裂韧性(K1c)和疲劳裂纹扩展门槛值(△Kth)有所提高,冲击韧性(αk)提高1倍以上,耐磨性也明显提高,各项性能指标达到了锻造高速钢水平,RE-Mg-Ti变质低碳铸造高速钢,有望实现“以铸代锻”。 相似文献
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研究了在RE528热作模具钢中加入不同含量稀土后,对组织、强度、硬度、冲击韧性和塑性的影响。结果表明:稀土的加入改变了硫化物夹杂物的形态,改善了钢中共晶碳化物的偏析程度,细化了晶粒,改善了钢液纯净度,提高了RE528钢的综合力学性能。 相似文献
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通过10kg真空中频感应炉熔炼、扫描电镜、能谱分析和Gleeble-1500试验机热模拟试验研究了0~0.072%La对20钢夹杂物、组织和高温拉伸性能的影响。结果表明,经稀土金属镧对钢中MnS、Al2O3等夹杂物变质处理后,形成尺寸≤2μm的椭圆体和球形RE2O3、RE2O2S和RES稀土夹杂物,显著提高20钢在850~1050℃的热塑性,与未加La钢相比,高温拉伸后水冷的马氏体板条组织更细。 相似文献
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对常规430铁素体不锈钢进行了稀土微合金化改进,最终开发出高品质430RE铁素体不锈钢冷轧退火带钢,并研究了稀土微合金化对430不锈钢的力学性能、深冲性能、抗皱性能、显微组织和织构的影响。通过稀土微合金化,430不锈钢中尺寸较粗大的CaO·SiO2和Al2O3·CaO夹杂物,大多转变为430RE不锈钢中尺寸较细小、分布密度较高的富含稀土元素的夹杂物。与采用基本相同热轧、冷轧和退火工艺的430不锈钢相比,430RE热轧板和冷轧退火板的强度水平均有所降低、塑性水平均明显升高;430RE生产过程中的宏观织构演变表现出更强的高塑性应变比(r值)γ-织构组分形成趋势,这使得430RE冷轧退火板的深冲性更优;430RE冷轧退火组织中沿轧向偏聚、低r值取向晶粒簇减少,这使得430RE冷轧退火板的抗皱性更优。 相似文献
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采用不同淬火方式(沙冷,雾冷,油冷,水冷)处理M42高速钢,通过SEM、AFM、XRD及维氏硬度仪研究不同冷却速率(1~35℃/s)对该合金微观组织与硬度的影响。结果表明,随淬火冷却速率增大:冷却过程中碳化物析出减少,淬火态残余奥氏体量增加;回火马氏体尺寸从150~200 nm减少到30~60 nm,马氏体晶界上二次碳化物析出量增多且尺寸减小;淬火态合金硬度从835 HV降低至788 HV,回火时二次硬化效果更加明显,回火态合金硬度从945 HV升高至1 002 HV,红硬性硬度从856 HV升高至924 HV。 相似文献
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The effect of rare earth elements on the thermal cracking resistance of high speed steel (HSS) rolls was investigated. Laser rapid heating was used for thermal fatigue experiments. Thermal cracks and microstructure were observed using metalloscopy and scanning electron microscopy. The results showed that thermal cracks initiated from the interface between the matrix and eutectic carbides (including M6C and M7C3 type carbides),and propagated along the interface between the two phases. MC type carbides enriched with vanadium could prevent the propagation of thermal cracks. The presence of rare earth elements decreased the quantity of big eutectic carbides,and proportionally increased spherical and rod-shaped MC type carbide content. HSS0 (0.00% RE) had approximately three times the thermal cracking density of HSS3 (0.12 wt.% RE). Rare earth elements were shown to significantly improve the microstructure and thermal cracking resistance of HSS rolls. 相似文献
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Saied El‐Ghazaly Tarek EI‐Gammal Ahmed EI‐Sabbagh Adel Nofal Mohammed Abbas 《国际钢铁研究》2001,72(2):58-65
The main problem of near‐net‐shape cast high speed steel toolings is the bad toughness due to the presence of relatively coarse structure and eutectic brittle carbide network. To overcome this problem intensive secondary cooling in oil immediately after casting was achieved, however special standard tool steels with high amount of austenite stabilizing elements were selected to give austenite + carbide in as‐cast condition. This eliminates the risk of martensitic transformation during intensive secondary cooling. Prespherodisation heat treatment at different temperatures was applied to improve the carbide morphology in cast structures of these steels. This is because traditional hardening of high speed (TS‐1 and TS‐2) cast steels showed severe deterioration in carbide morphology and increased noncoherency with the matrix. In this case, skeleton brittle carbide morphologies were detected in such steels. Impact toughness of prespherodised hardened high speed cast steel (TS‐2) was more or less higher than that of the normally heat treated steel, especially at section sizes lower than 20 mm. Meanwhile the prespherodised steel showed lower toughness at section sizes of more than 20 mm. The hot hardness for the same thickness and test temperature of normally hardened high speed steels was higher to some extent than that for prespherodised and hardened ones. However, the hot hardness increases as the size of sample increases, due to the gross of eutectic and secondary carbide. 相似文献
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The influence of rare earths(RE) on solidification behavior of a high speed steel for roll was investigated by using differential scanning calorimetry(DSC) in combination of microstructure analysis.It was found that the sequence of solidification was L→γ,L→γ+MC,L→γ+M2C,L→γ+M6C,respectively.The start temperature and the latent heat liberated by unit mass of L→γ and L→γ+MC increased with increase of RE addition,indicating that RE could trigger the crystallization of the primary γ and the MC carbide more effectively.The promoting effect of RE on the heterogeneous nucleation was believed to be an important cause of this effect.Grain refinement,discontinuous network of eutectic carbides and disperse and finer MC were observed in the samples with RE addition,moreover,RES could act as the heterogeneous nucleus of the MC.RE addition was favorable for stable M6C at the expense of the metastable M2C. 相似文献
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采用XRD,SEM及力学性能测试等方法研究添加稀土氧化物Y2O3、CeO2和(Y2O3+CeO2)对羟基磷灰石基复合材料的烧结温度、力学性能和显微结构的影响。结果表明,添加2%的稀土氧化物,可以降低烧结温度,改善显微结构,提高抗弯强度。尤其是添加2%的复合稀土氧化物(Y2O3+CeO2)后,羟基磷灰石基复合材料的抗弯强度达110 MPa,是未添加稀土氧化物的试样的1.29倍。其强度提高的主要原因是稀土元素的细晶强化和固溶强化等对基体的作用。 相似文献
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Effects of Ti, V, and rare earth on the mechanical properties of austempered high silicon cast steel
The microstructure and mechanical properties of austempered high silicon cast steel pro and after treating with a modifier
containing titanium, vanadium, and rare earth metals (so-called Ti-V-RE modifier) and austempered at different temperatures
are investigated. The results show that the dendritic austempered structure and the blocky retained austenite are reduced
after treating with the Ti-V-RE modifier. The modification can obviously improve the mechanical properties of austempered
high silicon cast steel. The austempering temperature at which the optimum impact toughness is obtained shifts from about
320 °C for the steel unmodified to about 360 °C for the steel modified. High impact toughness is obtained in austempered high
silicon cast steel high silicon cast steel when the retained austenite amount is about 15 to 25 pct for the modified steel
and 20 to 35 pct for the unmodified steel. 相似文献
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在Gleeble- 3800热模拟机上进行了高速工具钢W6Mo5Cr4V2(M2)钢热模拟试验,测试了从650℃到1250℃温度M2钢的高温力学性能,得到了抗拉强度曲线和热塑性曲线,观察了不同温度下试样的金相组织和断口形貌。试验结果表明:M2高速钢的零塑性温度为1220℃,零强度温度为1250℃。良好的塑性温度区为950~1150℃,脆性区主要为1175℃至熔点,在850~950℃存在一个较弱的脆性区。在800℃附近,还存在一个良好的低温超塑性区。分析表明,M2高速钢的高温力学性能与基体组织的相变、碳化物的溶解和低熔点碳化物的熔化有很大关系。 相似文献