高速鋼刃具 快速退火法

高速钢刃具返修时,我们采用盐浴炉快速退火来代替电炉等温退火,退火时间由原来12小时缩短到3小时,提高工作效率4倍左右。快速退火的工艺是:将急于返修并要退火的刃具用鉄丝捆扎或用盘装,放在880～900℃中型电极盐浴炉(C—45型,盐浴成分是氯化银78％ 氯化钠22 ％)中加热,保温0.5～1小时后取出,把工件降温到720～750℃等温1～1.5小时,再降温到600℃左右出炉空气冷却。这种方法只适用于返修的高速钢刃具;盐浴炉可以采用高速钢刀具第二次予热炉。退火结果,硬度在布氏205～255,金相     

退火工艺对机用锯条淬火回火硬度及锯切寿命的影响

对W9Mo3Cr4V高速钢机用锯条进行了退火工艺试验和锯切寿命试验 ,试验结果表明 ,不同退火工艺与锯条淬火回火硬度及锯切寿命之间不存在明显对应关系 ,但高温长时间退火对锯切寿命有不利影响。     

高速钢的退火方法

一、高速钢退火方法高速钢经锻造空冷后金相组织为:马氏体+少量的屈氏体+碳化物,硬度HRC56～62。故锻造后必须经过退火处理,降低硬度,便于切削加工,并为淬火作好组织准备。退火方法有多种,简述如下。     

国外刀具热处理技术近况（二）

国外刀具热处理技术近况（二）机械部成都工具研究所（６１００５６）李惠友二、国外刀具热处理工艺近况互．高速钢退火新工艺高速钢退火周期很长，短则十几小时，长者达几十小时。前苏联对高速钢退火工艺进行了根本性的变革，大大缩短了退火周期．并且提高了钢材的退火质...     

变质M2高速钢稀土离子硫碳氮共渗研究

对Y-K-Na复合变质的M2高速钢进行离子硫碳氮共渗和稀土离子硫碳氮共渗处理,研究稀土元素对复合变质M2高速钢离子硫碳氮共渗组织和性能的影响。试验结果表明:稀土元素改善变质M2高速钢渗层组织,提高表面硬度,使渗层硬度梯度平缓,可有效地提高其抗摩擦磨损的能力。     

改善高速钢加工性能的方法

各种制造刀具用的高速钢胚料,在钢厂出厂以前,大都经过退火处理,因此它的硬度一般都在 HB205～255。由于在退火时冷却过程很长,因此在钢料晶粒的边缘,会析出很细小的合金化合物,使钢料的加工性能和塑性都很低。为了改善它的加工性能和塑性,可用下列的方法:一、把没有经过锻造的高速钢胚料(即已经在钢厂内退过火的热轧型钢),放在箱式炉或盐浴炉内加热到720°～740℃,根据     

改善高速钢加工性能的方法

各种制造刀具用的高速钢胚料,在钢厂出厂以前,大都经过退火处理,因此它的硬度一般都在HB205～255。由于在退火时冷却过程很长,因此在钢料晶粒的边缘,会析出很细小的合金化合物,使钢料的加工性能和塑性都很低。为了改善它的加工性能和塑性,可用下列的方法: 一、把没有经过锻造的高速钢胚料(即已经在钢厂内退过火的热轧型钢),放在箱式炉或盐浴炉内加热到720°～740℃,根据     

用铝高速钢制滚刀滚切中硬齿面齿轮

<正> 昆明市第二机器厂继用高速钢插齿刀成功地插削硬度达HRC48～52的齿轮之后,又于1984年用高速钢滚刀滚切硬度达HRC40～48齿轮的试验,并取得了较为满意的效果。由于技术和经济效益较好,该厂已将其纳入了正式工艺。     

高速钢和45钢焊接毛坯循环退火的试验研究

为软化高速钢和45钢摩擦焊接毛坯焊缝处的硬度,以利于机械加工,本文研究了循环退火方法,即在A_1点附近,进行循环加热和退火,达到软化目的。本文通过正交试验,选出了最佳工艺参数。     

高速钢的快速单级循环退火

<正> 目前广泛采用的高速钢退火方法—连续冷却退火和等温退火的显著特征是持续时间相当长,分别为20～30小时和15～18小时。为了缩短退火过程的时间,有人曾推荐两种高速钢快速退火法。第一种方法是在同一盐浴炉中进行的无级循环退火,其特点是不断改     

保温时间对ATN陶瓷刀具材料力学性能及显微结构的影响

为了开发一种陶瓷刀具材料,以Al2O3/TiN为主要成分,利用热压烧结工艺,在烧结温度1700℃,烧结压力32MPa条件下制备了复合陶瓷材料.FiN含量取30%、40%、50%、60%,保温时间取5min、10min、15min.研究了四种配比的材料在不同保温时间下抗弯强度、硬度、断裂韧性等力学性能与材料显微结构的关系...     

Substrate dependence of the scratch resistance of CrN<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript> coatings on steel

Hard CrN_x coatings were sputter deposited on hot work tool steel (HWTS) and high speed steel (HSS) in an industrial PVD reactor. Coatings were deposited under various nitrogen flows. The thickness, density, hardness, elastic modulus, composition, and stress were determined for the coatings. The specimens were subjected to scratch testing. Two different failure mechanisms were investigated: chipping and complete coating removal. For all specimens, the coating-to-substrate adhesion was that good that adhesion did not limit the scratch resistance. Therefore, the minimum loads at which a given type of failure was initiated were not a measure for the coating-to-substrate adhesion. The scratch resistance was better for coatings on HSS than for coatings on HWTS. This is due to the higher hardness of the HSS. Substrate independent measures for the scratch resistance of the coating were obtained by considering critical track widths instead of critical loads. The hardening of the coating--substrate systems due to the coating was investigated. The uncoated substrates exhibited track width independent scratch hardness. For the coated specimens the scratch hardness increased with increasing track width until chipping of the coating occurred. Complete coating removal coincided with a decrease in hardness. Although the elastic properties, hardness, and thickness of all coatings were more or less equal, CrN_1.0 coatings outperformed CrN_0.6 coatings in scratch tests both on HSS and on HWTS.     

喷射成形高速钢的组织和性能

研究了喷射成形工艺对高合金化高速钢组织和性能,结果表明:喷射成形工艺制备了直径300mm高合金化高速钢沉积坯,表面质量良好,可以满足直接锻造要求。喷射成形高速钢组织无宏观偏析,碳化物呈现均匀弥散分布在晶界和晶内,主要有M6C和MC两种碳化物相,氧含量只有约20ppm左右。经过热处理后,喷射成形T15合金的抗弯强度平均达到4800MPa。硬度随着淬火温度的提高逐渐升高,喷射成形T15M合金在1250℃淬火后,硬度达到了69.3HRC。     

汽轮机转子锻件高温扩散退火工艺的试验研究

基于试验方法,结合高中压汽轮机转子锻件实际生产工艺,研究了不同保温时间、锻造火次处理后晶粒尺寸、组织、力学性能的变化规律,揭示了高温扩散退火对30Cr1Mo1V钢的影响。试验结果表明：高温扩散退火可消除因枝晶偏析与锻造变形产生的条带组织;只在锻前进行高温扩散退火,试样晶粒尺寸较小,且扩散的均质化作用提高了30Cr1Mo1V钢的横向韧性;锻后长时间高温加热将导致晶粒过大、组织粗化,大大降低了韧性;高温扩散退火对30Cr1Mo1V钢塑性无显著影响。     

Experimental investigation of thixoforging parameters effects on the microstructure and mechanical properties of the helical gearbox cap

The purpose of this work is to discuss the microstructures and mechanical properties of thixoforged helical gearbox caps. The mechanical properties of semi-solid components can be improved by controlling the process parameters such as solid fraction of alloy, die temperature, applied pressure, punch velocity, and heat treatment conditions. In this paper, the effects of forming parameters on the microstructures and mechanical properties of thixoforged A356 helical gearbox caps with an arbitrary shape are studied. The mechanical characteristics were investigated by changing the applied pressure, die temperature, specimen temperature and holding time. The results showed that by increasing the applied pressure from 100 MPa to 150 MPa, the average grain diameter was decreased about 7% and the shape factor was increased about 11%. Also, by increasing the die temperature, the hardness and forming load were decreased about 13% and 21%, respectively. The results illustrated that by increasing the specimen temperature and holding time, there would be an increase in the grain size of primary α-Al phase, so the hardness of the specimens is decreased.     

锰对高铬铸铁奥氏体冷却转变过程的影响

研究了锰对高铬铸铁奥氏体冷却转变过程的影响。研究结果表明,锰增加奥氏体化温度下碳和合金元素的平衡浓度,从而大大增加奥氏体的稳定性;在液火冷却转变中,锰增加合金的淬透性,提高大截面锰铸的淬火硬度,但增加小截面铸件的残余奥氏体量;在退火冷却转变中,锰使退火变得困难,退火硬度有所增加;以锰提高高铬铸铁的淬透性是十分有效的,但其加入量应与铸件截面尺寸相适应。     

M42高速钢刀具的抗弯强度试验及分析

通过抗弯强度试验分析了M42高速钢刀具的热处理硬度与韧性之间的关系 ,提出采用等温淬火工艺将M42高速钢刀具的硬度控制在 6 5～ 6 7.5HRC可获得较佳切削性能。     

Study of microstructural influences on machinability of case hardening steel

The overall aim of this study is to establish knowledge about how the material specification of case hardening steel should be modified in order to create a robust and predictable production process with focus on machinability. In this study, emphasis is laid on studying microstructure variations produced by changing holding time and temperature in the annealing process. A standardized milling test was used to assess machinability (with respect to tool wear) as this method has the advantage of only needing small diametrical samples and low material volumes. From the results of the test, it can be concluded that machinability is more influenced by pearlite nodular size than by pearlite morphology. Furthermore, it can be stated that hardness is not a suitable criterion for determining machinability of case hardening steel. In the manufacturing process of transmission parts (such as gear milling/hobbing), high speed steel tools are commonly used. The same type of tool is applied in the standardized milling test. However, the obtained ranking (of machinability) for the different materials is also applicable if other types of cutting tools are used.     

锯片铣刀的热处理工艺及其寿命的实验研究

本文对“M2”高速钢板制造的锯片铣刀所作的热处理工艺试验、红硬性试验和刀具寿命试验进行了分析。经试验分析得出,热处理工艺采用1230℃淬火,560℃三次回火,刀具硬度、奥氏体晶粒度、红硬性均在合格范围内,采用此种热处理工艺刀具使用寿命最佳。     

深冷处理对W9Mo3Cr4V刀具耐磨性能影响的研究

采用微机控制的刀具深冷处理装置对W9Mo3Cr4V高速钢成品刀具进行深冷处理研究。对深冷处理后的刀具和未经深冷处理的刀具在硬度、耐用度及金相显微结构方面进行了实验对比。结果表明，深冷处理可以改变高速钢刀具材料的微观组织结构，并在一定程度上提高刀具材料的硬度，增强刀具材料的耐磨损性能。分析了产生这种变化的机理。