车轮的感应加热淬火工艺

分别采用同时加热淬火方式和连续加热淬火方式对45钢锻件车轮进行感应淬火研究。结果表明：采用连续加热淬火方式(感应器与工件间隙6 mm、输出功率为339 kW、频率为6.3 kHz),用清水进行喷淋冷却,然后对其进行230℃×2 h炉中回火处理后,车轮外表面踏面及倒圆角区域的表面硬度为509～599 HV0.2(50～55 HRC)、淬硬层深度为3.4～4.7 mm、显微组织级别为5～7级,均能达到其技术要求,并在工业化试生产中取得了较好的应用效果。     

MC5钢感应加热淬火工艺参数

用铅浴淬火试验模拟感应加热,对MC5冷轧工作辊的感应加热淬火工艺进行了试验.预备热处理宜采用910℃淬火,660～680℃回火.感应加热淬火温度在930～950℃之间,轧辊的下降速度为0.5mm/s.     

50CrVA钢板簧淬火开裂原因分析

一种汽车板簧以热轧态的50CrVA弹簧钢为原料,经锻造(1030±20) ℃×(30~40 min)→ 900 ℃加热预处理→(860±20) ℃淬火→485 ℃回火热处理后,产生淬火裂纹,对其产生原因进行了分析。结果表明,50CrVA钢热处理后组织中出现混晶、带状偏析等缺陷是淬火裂纹产生的主要原因;900 ℃预处理保温40 min有利于减少缺陷,避免产生淬火裂纹。     

铁路扣件用含铌弹簧钢感应加热淬火的组织与性能

研究了含铌弹簧钢扣件感应淬火和空气电阻炉加热淬火的显微组织及硬度分布特点。结果表明：感应加热可以改善试验钢的组织均匀性,避免空气炉加热过程中出现的表面脱碳现象;含铌弹簧钢适宜的感应淬火温度为1000℃。     

30CrMnSiNi2A钢零件感应加热局部回火工艺

对30CrMnSiNi2A钢零件进行感应加热局部回火试验,参照铅浴局部回火工艺的相关技术要求,对感应加热热处理的设备、工艺等进行摸索,获得了符合生产要求的感应加热局部回火工艺。试件感应加热局部回火后的疲劳性能和对缺口敏感性的降低都较铅浴局部回火要好。     

Punching of small hole of die-quenched steel sheets using local resistance heating

A punching process of a small hole in a die-quenched steel sheet having high strength using local resistance heating of a shearing zone was developed to decrease the punching load. Uniform temperature in the circular shearing zone of the hole was obtained by optimising heating conditions for a pair of rectangular electrodes. The punch load and the burnished surface area for the heating at 500 °C were about 1/3 smaller and 2 times larger than those for the cold punching, respectively, and the occurrence of delayed fracture around the punched hole was prevented by the heating above 500 °C.     

Mathematical model of plasma heating for quenching

A mathematical model that makes it possible to determine the main laws of surface heating of a large steel part by a high-enthalpy plasma jet with the aim of optimizing the technology of surface plasma hardening of wheel pairs of rolling stock is suggested. Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 5, pp. 29–31, May, 1999.     

Punching of ultra-high strength steel sheets using local resistance heating of shearing zone

A punching process using local resistance heating of a shearing zone was developed to shear ultra-high strength steel sheets. The shearing zone was heated by passing electric current between the sheet holder and the knockout in order to decrease the flow stress in the shearing, and the heating of the die and punch was prevented by no contact with the sheet during the heating. Electrode pins having an individual spring were employed to attain uniform heating of the shearing zone. The welding resistance of the heads of the electrode pins to the sheet by the heating was examined for Ag-W, Cu-W, Ag + WC and W. The Cu-W pins having the highest welding resistance were employed in a punching experiment of 980 MPa level ultra-high strength steel sheets. The punching load was considerably reduced by the heating, e.g., about 1/5 of the cold punching load at 800 °C. As the heating temperature increased, the depth of the shiny burnished surface on the sheared edge increased and that of the rough fracture surface decreased.     

碟形弹簧的模压淬火

图1所示的碟形弹簧是夹具系统的重要零件之一.工作时碟形弹簧承受交变应力,因此要求它有高的弹性极限及屈强比,以保证多次受力不产生塑性变形.在精度方面要求虽不算高,但两端面的接触带(支承面)因组合需要,必须平行并与轴向垂直,不能有翘曲.     

Cr含量和加热温度对高铁弹条用60Si2Mn弹簧钢脱碳层的影响

通过提高高铁铁轨扣件系统中的弹条用60Si2Mn弹簧钢中的Cr元素含量,分析了不同加热温度下钢的脱碳情况,研究了Cr元素以及加热温度对60Si2Mn弹簧钢脱碳层组织形貌及厚度的影响.结果表明,Cr元素含量提高至0.35％后,弹簧钢在不同加热温度下的脱碳层厚度都有明显减少,当加热温度在900℃以上时只存在部分脱碳现象,且...     

淬火温度对60Si2CrVAT弹簧钢组织与性能的影响

对60Si2CrVAT弹簧钢不同温度条件下的淬火工艺进行了优化,研究淬火温度对微观组织和力学性能的影响规律,并对显微组织、力学性能、疲劳性能及其之间的关系进行了分析。研究结果表明：60Si2CrVAT钢淬火温度采用910±10 ℃时（410 ℃回火）,综合力学性能达到最佳。微观组织分析结果表明：淬火组织中马氏体针长度应控制在0.03 mm之内,可保证弹簧服役性能。     

钢管内喷旋流淬火技术

在简要回顾钢管淬火技术和设备现状的基础上,介绍了一种新型的钢管内喷旋流淬火技术的原理、特点和设备及技术组成,并在实际生产运用中证明了钢管内喷旋流淬火具有设备结构简单、淬火冷却均匀,运行维护费用低等特点.该项技术用于钢管的淬火处理能获得较高质量.     

45钢淬火工艺的改进

45钢是一种应用广泛的机器零件用钢,属中碳范畴,其化学成分(质量分数,％)为:0.42 ～0.50C、0.17～0.37Si、0.5～0.8Mn、≤0.25Cr,微量V.有关温度参数为:Ac1=735℃,Ac3=785℃,Ms=350℃,Ar3=750℃.完全淬火后其组织为板条马氏体(M)和片状马氏体的混合组织,由于含碳量相对较高,组织内含丰富位错和孪晶结构,因而其强度较高,但塑性和韧性不足.经适当回火后,可获得良好的综合力学性能.大量军工产品工装零件和民品零件都采用45钢.经多年实践,发现45钢的传统淬火工艺并不完美,需要补充和改进.