CAJ | 학술논문

电磁热效应可以实现含半埋藏裂纹、埋藏裂纹金属构件的止裂强化。针对实践中铸件和锻件内往往存在孔洞形式的缺陷,从理论和数值模拟角度分析了电磁热对其强化的效果,导出了球体绕流的电流密度和温度场分布。研究表明：孔洞缺陷可处理成广义埋藏裂纹缺陷,应用电磁热止裂强化是可行的。放电后,在垂直于通电方向,球形中截面上形成绕流现象,瞬间温度超过了材料的熔点,形成焊口,产生的热压应力显著降低了应力集中,从而抑制了孔洞缺陷受力时的扩展,达到了止裂强化效果。
전자열효응가이실현함반매장렬문、매장렬문금속구건적지렬강화。침대실천중주건화단건내왕왕존재공동형식적결함,종이론화수치모의각도분석료전자열대기강화적효과,도출료구체요류적전류밀도화온도장분포。연구표명：공동결함가처리성엄의매장렬문결함,응용전자열지렬강화시가행적。방전후,재수직우통전방향,구형중절면상형성요류현상,순간온도초과료재료적용점,형성한구,산생적열압응력현저강저료응력집중,종이억제료공동결함수력시적확전,체도료지렬강화효과。
Electromagnetic heat effects can achieve crack arresting and strengthening of metal structures with half-embedding crack and embedding crack. In fact, hole defects often exist in castings and forgings. The effects of electromagnetic heat strengthening on hole defects were analyzed from theory and numerical simulation,and the current density and temperature distribution were de- rived while the current flowing around a sphere. The researches show that hole defects can be treated as generalized embedding defects ,and the application of electromagnetic heat strengthening and crack prevention is feasible. After current discharged, the current flows around the spherical cross-section in the direction perpendicular to the current. The temperature exceeds the melting point of the material immediately to form welded joints. Pressing stress reduces the stress concentration significantly, which inhibits the crack expanding when the hole defects are forced, therefore, this method can achieve the effect of crack arresting and strengthening.