Grinding hardening is a new technology of hardening steel piece surfaces with grinding heat generated in the grinding process instead of with a high or medium frequency induction heating method,which can effectively i...Grinding hardening is a new technology of hardening steel piece surfaces with grinding heat generated in the grinding process instead of with a high or medium frequency induction heating method,which can effectively integrate grinding and surface hardening. Experimental studies were carried out on grinding hardening of non-quenched and tempered steel. Through grinding experiments with variable depths of cut and feeding rate,the variation in the depth of the hardening layer was studied and the microstructure of the hardening zone of the test pieces was subsequently ana-lyzed. In the end,the hardening effect of non-quenched and tempered steel was compared with that of 40Cr steel,which revealed the superiority of non-quenched and tempered steel in grinding hardening technology.展开更多
ERH end-quenching method was used to determine the hardenability of four kinds hot-forging die steels with deep-hardening and hence the order of their hardenability was given.The tempering hardness of the steels was m...ERH end-quenching method was used to determine the hardenability of four kinds hot-forging die steels with deep-hardening and hence the order of their hardenability was given.The tempering hardness of the steels was measured and the tempering resistance was studied.It was approved that ERH method is effective for the determination of hardenability of deep-hardening steel and the beginning of hardness drop in the ERH specimen is caused by bainite occurring.展开更多
In this paper, the microstructure and strengthening mechanism of 23NiCo steel were studied by transmission electron microscopy and atom-probe field-ion microscopy. The results show that the peak strength obtained when...In this paper, the microstructure and strengthening mechanism of 23NiCo steel were studied by transmission electron microscopy and atom-probe field-ion microscopy. The results show that the peak strength obtained when the steel is tempered at 440455℃is due to the precipitation of coherent zones of fine carbides.The peak in toughness attained at the absence of cementite and the formation of reverted and stable austenite.Tempering at higher temperatures resulted in loss of both strength and toughness. The drop of the strength of the steel tempered at high temperature is due to precipitation coarsening and loss of coherence with the matrix.展开更多
近年来开发的高 Co Ni超高强度合金钢 ,以其合理的合金设计、极高的力学性能和使用性能而获得广泛的关注。高 Co Ni合金钢是典型的马氏体时效钢 ,它利用时效处理析出的细小弥散M2 C合金碳化物达到二次强化的目的 ,从而获得强度与韧性的...近年来开发的高 Co Ni超高强度合金钢 ,以其合理的合金设计、极高的力学性能和使用性能而获得广泛的关注。高 Co Ni合金钢是典型的马氏体时效钢 ,它利用时效处理析出的细小弥散M2 C合金碳化物达到二次强化的目的 ,从而获得强度与韧性的最佳配合。作者从材料开发、性能。展开更多
基金Projects JH03-001 supported by the High and New Technology Foundation of Jiangsu High School2006B009 by the Science Foundation of China University ofMining & Technology
文摘Grinding hardening is a new technology of hardening steel piece surfaces with grinding heat generated in the grinding process instead of with a high or medium frequency induction heating method,which can effectively integrate grinding and surface hardening. Experimental studies were carried out on grinding hardening of non-quenched and tempered steel. Through grinding experiments with variable depths of cut and feeding rate,the variation in the depth of the hardening layer was studied and the microstructure of the hardening zone of the test pieces was subsequently ana-lyzed. In the end,the hardening effect of non-quenched and tempered steel was compared with that of 40Cr steel,which revealed the superiority of non-quenched and tempered steel in grinding hardening technology.
基金Project sponsored by Research Fund for Doctoral Program of Higher Education(9514509)
文摘ERH end-quenching method was used to determine the hardenability of four kinds hot-forging die steels with deep-hardening and hence the order of their hardenability was given.The tempering hardness of the steels was measured and the tempering resistance was studied.It was approved that ERH method is effective for the determination of hardenability of deep-hardening steel and the beginning of hardness drop in the ERH specimen is caused by bainite occurring.
文摘In this paper, the microstructure and strengthening mechanism of 23NiCo steel were studied by transmission electron microscopy and atom-probe field-ion microscopy. The results show that the peak strength obtained when the steel is tempered at 440455℃is due to the precipitation of coherent zones of fine carbides.The peak in toughness attained at the absence of cementite and the formation of reverted and stable austenite.Tempering at higher temperatures resulted in loss of both strength and toughness. The drop of the strength of the steel tempered at high temperature is due to precipitation coarsening and loss of coherence with the matrix.
