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文摘
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如何产生高强度脉冲电流是应用电磁热效应遏制金属裂纹研究的一个关键问题.本文介绍了高压脉冲放电装置的工作原理;从理论上分析了充电电压、回路参数与放电电流幅值、放电周期之间的关系.在此基础上,自主设计、开发了一套高压脉冲放电装置.采用它对金属模具钢中裂纹进行了脉冲放电止裂实验.放电时裂纹尖端熔化形成堆焊和高压应力区,使裂纹尖端钝化,达到了止裂的目的.由于脉冲放电快速加热和冷却,在裂纹尖端处实现了冲击淬火,得到了超细化的隐晶马氏体和细粒碳化物等微观组织,提高了裂纹尖端处的硬度、强韧性和耐磨性,试验结果验证了该装置的有效性,本文的成果为采用电磁热效应对金属模具裂纹止裂提供了实验技术基础. |
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其他语种文摘
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How to produce powerful pulse current is a key problem in the crack arrest by electromag-netic heat effect. In this paper, the principle of high pulse discharging was introduced. The relation-ship among charge voltage, circuit parameter and value of discharge current was analyzed. The dis-charge equipment was self designed and developed. Tests of crack arrest were executed at the crack tip of the metal die steel through pulse current discharge with the high voltage pulse current generator. The crack tip was melted, welded joints were formed and higher compressive stresses could be pro-duced around the crack tip while the pulse current was switched on. The crack tip was blunted) so the crack was prevented. Because the heating and cooling was super fast while pulse current was switched on the impulse quenching was achieved around the crack tip. The superfine cryptocrystal martensite and fine-gray carbon compound appeared. The intensity, ductility and wearing capacity around the crack tip were promoted. The effective of the current generator is verified by the results of experi-ments. The present achievement provides a basis of experimental technique for crack arrest in metal dies using electromagnetic heating. |
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来源
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实验力学
,2005,20(3):411-416 【核心库】
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关键词
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电磁热效应
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裂纹止裂
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高压脉冲放电
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装置开发
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地址
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1.
中国科学院力学研究所, 国家非线性连续介质力学重点实验室（LNM）, 北京, 100080
2.
中国科学院力学研究所, 国家非线性连续介质力学重点实验室, 北京, 100080
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语种
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中文 |
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文献类型
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研究性论文 |
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ISSN
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1001-4888 |
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学科
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力学 |
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基金
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国家自然科学基金资助项目
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文献收藏号
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CSCD:2017805
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