SURFACE TREATMENT FOR STEEL SPRING

• Main Authors: HIJIKATA NAOKI, KOSONE TOSHIO
• Format: Patent
• Language: English
• Published: 21.12.1988
• Subjects: ABRASIVE OR RELATED BLASTING WITH PARTICULATE MATERIAL; BLASTING; CHEMICAL SURFACE TREATMENT; CHEMISTRY; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATIONOR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY IONIMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING MATERIAL WITH METALLIC MATERIAL; COATING METALLIC MATERIAL; DIFFUSION TREATMENT OF METALLIC MATERIAL; ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVEFUNCTIONING OF MACHINES OR INSTALLATIONS; GRINDING; HEATING; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL; LIGHTING; MEANS FOR DAMPING VIBRATION; MECHANICAL ENGINEERING; METALLURGY; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLICMATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASSC23 AND AT LEAST ONEPROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25; NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; PERFORMING OPERATIONS; POLISHING; SHOCK-ABSORBERS; SPRINGS; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THESURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; THERMAL INSULATION IN GENERAL; TRANSPORTING; WEAPONS

PURPOSE:To improve the fatigue strength of a steel spring, by applying Ni-type electroless plating treatment to the surface of a steel spring and subjecting the above spring to shot peening treatment. CONSTITUTION:The surface of a steel spring is plated with Ni-base alloy, such as Ni-P alloy and Ni-B alloy, by an electroless plating method. Subsequently, the spring is annealed at 200-400 deg.C and then subjected to shot peening treatment to establish compressive residual stress in the spring, by which the occurrence of fine cracks at the spring surface can be prevented even after long use and the steel spring excellent in fatigue strength can be manufactured.