In this paper, 1Cr11Ni2W2MoV steel that is aerial engine blade materials was hot dipped Al-6%Si-4%RE in order to improve its application temperature. According to GB/T13303-91 standard, samples with coating and withou...In this paper, 1Cr11Ni2W2MoV steel that is aerial engine blade materials was hot dipped Al-6%Si-4%RE in order to improve its application temperature. According to GB/T13303-91 standard, samples with coating and without coating were oxidated at 700℃ from 5 h to 600 h. Two oxidation kinetics curves were drawn in terms of data of tests. The results showed that oxidation resistance of 1Cr11Ni2W2MoV steel hot-dipped Al-6%Si-4%RE is better than one without coating. From SEM and EMPA, the surface of coating formed dense and uninterrupted α-Al2O3, which is the bars of oxidation resistance. In addition, according to one crossing point of the two curves, it was suggested that hot dipped aluminum steel should be annealed before used.展开更多
Design reliable and safe LED （light emitting diode） lighting equipment for potentially explosive atmospheres should require knowledge about the possible failure modes of LED sources. Nowadays, LED technology potenti...Design reliable and safe LED （light emitting diode） lighting equipment for potentially explosive atmospheres should require knowledge about the possible failure modes of LED sources. Nowadays, LED technology potential is not adequately considered by IECEx （International Electrotechnical Commission system for certification to standards relating to equipment for use in explosive atmospheres） yet. Standards only consider LEDs adequate for Zone 1 when luminary is realized by the Ex-d protection strategy, or ifa big limitation in terms of power is guarantee, for Ex-i mode. In particular, Ex-d LED luminaries are obtained by using heavy, thick and expensive flameproof enclosures, entrusting safety only to the mechanical strength of the case. Luminous efficiency＇s also reduced since the glass used is very thick （10% reduction of approximately every 10 mm of thickness of the glass）. The paper shows a study about different possible causes of LED failure and their implication with explosive atmospheres, investigating whether LED technology can be used safely with other safety strategy like Ex-e, which can guarantee better performance and less cost.展开更多
文摘In this paper, 1Cr11Ni2W2MoV steel that is aerial engine blade materials was hot dipped Al-6%Si-4%RE in order to improve its application temperature. According to GB/T13303-91 standard, samples with coating and without coating were oxidated at 700℃ from 5 h to 600 h. Two oxidation kinetics curves were drawn in terms of data of tests. The results showed that oxidation resistance of 1Cr11Ni2W2MoV steel hot-dipped Al-6%Si-4%RE is better than one without coating. From SEM and EMPA, the surface of coating formed dense and uninterrupted α-Al2O3, which is the bars of oxidation resistance. In addition, according to one crossing point of the two curves, it was suggested that hot dipped aluminum steel should be annealed before used.
文摘Design reliable and safe LED （light emitting diode） lighting equipment for potentially explosive atmospheres should require knowledge about the possible failure modes of LED sources. Nowadays, LED technology potential is not adequately considered by IECEx （International Electrotechnical Commission system for certification to standards relating to equipment for use in explosive atmospheres） yet. Standards only consider LEDs adequate for Zone 1 when luminary is realized by the Ex-d protection strategy, or ifa big limitation in terms of power is guarantee, for Ex-i mode. In particular, Ex-d LED luminaries are obtained by using heavy, thick and expensive flameproof enclosures, entrusting safety only to the mechanical strength of the case. Luminous efficiency＇s also reduced since the glass used is very thick （10% reduction of approximately every 10 mm of thickness of the glass）. The paper shows a study about different possible causes of LED failure and their implication with explosive atmospheres, investigating whether LED technology can be used safely with other safety strategy like Ex-e, which can guarantee better performance and less cost.
