50th Anniversary of induction surface hardening

Conclusion Induction surface and bulk-surface hardening of steel in accordance with optimal regimes and the proper selection of the steels ensures the high in-service properties of various heavily loaded machine components.As a result, the induction hardening of steel is being carried out at the leading establishments of the truck, tractor, and machine-building industry, and is the basic method for the thermal hardening of components in many cases.The potential of induction heat treatment, however, is yet to be exhausted.Studies devoted to further expansion of the sphere in which this method is used, to the transfer of leading experience, and to raising the level of technology at all establishments utilizing induction heat treatment are critical and urgent.The further development, refinement, and implementation of induction heat treatment in machine building and metallurgy is a critical problem of scientific and technical progress in our country.Moscow Institute of Advanced Metallurgy. Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 8, pp. 2–10, August, 1987.     

一种压纹辊表面感应淬火工艺研究

介绍大辊径压纹辊采用中频感应表面处理替代原氮化表面处理,通过优化中频感应处理的工艺参数及改进中频感应设备,达到淬硬层厚、整体变形小,提高了大辊径压纹辊的使用寿命,缩短了生产周期,降低了生产成本。     

Technology and equipment for rational induction surface hardening of feed screws with recirculating balls

Conclusion At the National Enterprise Carl Zeiss Jena (East Germany) an improved method of continuous sequential induction hardening of feed screws with highly accurate length was worked out.The method was introduced into production jointly with the firm AEG-Elotherm (West Germany), which designed the corresponding equipment and apparatus.By continuous measurement of the length during continuous sequential surface hardening and immediate computer processing of the results of measurements it is possible by manual control of the speed of the inductor to maintain the elongation of the screw within previously specified narrow limits corresponding to the negative correction of the pitch of the thread envisaged in its cutting.Experience accumulated in recent years shows that the required absolute linear dimension of screws can be maintained with an accuracy of ±0.17 mm, regardless of the length of the screw (within the limits 0.5–4.0 m).Further improvement of the process will be effected chiefly by automating its control which at present is carried out manually.National Enterprise Carl Zeiss Jena (East Germany). AEG-Elotherm, Remscheid. Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 12, pp. 4–8, December, 1984.     

High-frequency induction hardening of the inner surface of thin-walled hollow cylinders

Conclusion We demonstrated the possibility of high-quality hardening with self-tempering of the inner surface of thin-walled hollow cylinders by means of slower one-time heating, resulting in no more than 0.5% distortion of the diameter and even hardening to a given depth.Pavlodar Tractor Plant. Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 10, pp. 69–71, October, 1970.     

A study and development of technology for surface induction hardening of railroad rails from low-alloy steel

A technology of heat treatment of railroad rails using induction heating has been developed and installed in the Azovstal' metallurgical works. It provides the requisite combination of properties in the metal of rail heads. However, the metal of the web and the bottom of the rails remains in the initial (unhardened) state. Under severe operational conditions (small-radius curves, high axial loads, and composite configuration of the road) the wear resistance of the head and the structural strength of the web and the bottom not hardened in the plant have to be increased. The properties of the rail steel can be improved by alloying it using the most effective and available elements. Currently, in Ukraine this is manganese. The present paper is devoted to the effect of manganese additives on the phase transformations in induction hardening and the specific features of the formed structure and properties of the rail steel. Optimum parameters for heat treatment of rails are recommended. Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 12, pp. 7–10, December, 1998.     

Steels with controlled hardenability for induction hardening

Conclusions Steels of the CH and LH type developed in the Soviet Union permit the use of a new method of induction hardening — bulk-surface hardening — and efficient utilization of the high-strength conditions (_b = 230–250 kgf/mm²). These steels make it possible to improve the structural strength, operating characteristics, service life, and reliability of critical heavily loaded machine parts.At the same time, CH steels make it possible to reduce by a factor of 2–3 the quantity of alloying elements, reduce the electrical energy for heat treatment, and completely exclude the cost of quenching oil for heat treatment in automatic equipment with high labor productivity, while retaining good working conditions. All this leads to substantial savings in production and operation. For example, when transmission gears (cylindrical and conical) are manufactured from LH steels the annual savings amount to more than 700,000 rubles at two automobile plants. Machine parts of CH steels — half axles and bearings in railway cars —have saved respectively six and four million rubles annually. The introduction of controlled-hardenability steels for induction hardening is a necessary condition for technological progress in machine construction and metallurgy.Moscow Evening Metallurgical Institute. Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 7, pp. 18–23, July, 1980.     

齿轮双频感应淬火技术

在齿轮生产中,机加工后的齿轮的齿部要通过热处理使之硬化,所采用的主要热处理工艺有渗碳、渗氮、感应淬火。感应淬火比前2种方法具有费用少、加工时间短、畸变小、节能、节省人工及场地等优点。目前,公认的感应加热电源均为一种频率,即使有多种频率电源,也非同时发生。因此为使齿轮类产品具有仿齿轮轮廓的淬硬层时,采取单一频率或不同时双频感应淬火很难得到仿形的淬硬层。     

GCr15钢表面感应淬火微观组织及室温干滑动磨损行为

研究了滚珠丝杠用GCr15钢表面感应淬火后的组织和磨损机理。采用SEM、显微硬度计和XRD分别观察和检测了表面感应淬火试样的微观组织、断口形态、从表层到芯部的显微硬度分布以及淬火相变硬化区的物相,分别在低、中、高磨损载荷下,对试样进行往复式线性干摩擦磨损测试,分析研究了摩擦系数、磨损表面和磨屑形貌。结果表明:相变硬化区主要由隐晶马氏体、残留奥氏体及弥散分布的粒状碳化物组成;表层到芯部的断口形态呈明显变化;随着载荷增加,摩擦系数降低;低载荷下磨损表面呈现轻微划痕和少量脱离的碳化物颗粒,发生轻微磨粒磨损;中载荷下主要发生磨粒磨损和轻微剥层磨损;高载荷下磨损表面有严重犁沟,磨屑呈大片状,主要发生剧烈磨粒磨损和剥层磨损。     

钻探工具管壁件局部感应淬火工艺改进

图1所示是一种钻探工具管壁件的一端,材料AISI4130钢,机加工后待局部高频淬火硬化即为成品。该零件外形尺寸75 mm×270 mm,一端带有舌头,热处理要求较为特殊,淬硬区域为端面开始以下5～6 mm长度范围内,螺纹处不允许硬化;舌头淬硬区域是从离舌头顶部6 mm开始以下区域,舌头顶部3 mm长度范围不允许硬化;硬化层深度要求≥0.76 mm,硬度要求40～50 HRC。     

防止零件表面尖角部位感应淬火开裂方法

为了防止零件表面尖角部位在感应淬火过程中发生开裂,设计了一种装置,可以将零件表面尖角部位完全遮盖。该装置同时可以避免因感应器与零件接触而造成短路,从而避免零件被电流击伤。结果表明：使用该防开裂装置及方法,不仅可以有效避免零件表面尖角部位在感应淬火过程中发生开裂,而且可以避免零件被电流击伤。