The toughness of ferritic steels is influenced by the grain size distribution, second phase, precipitates and coarse inclusions. In this work an examination of the effect of coarse TiN particles （〉0.5 μm） and ferr...The toughness of ferritic steels is influenced by the grain size distribution, second phase, precipitates and coarse inclusions. In this work an examination of the effect of coarse TiN particles （〉0.5 μm） and ferrite grain size on the Charpy impact transition temperature in high strength low alloyed steels has been carried out. Steels with high Ti content （up to 0.045 wt%）, have been heat-treated and furnace cooled to obtain a ferrite-pearlite microstructure with different ferrite grain sizes. Coarse TiN particle size and ferrite grain size distributions have been measured and Charpy impact testing has been carried out. Scanning electron microscopy （SEM） analysis has been used to measure the grain boundary carbide thickness and to determine if the coarse TiN particles are acting as cleavage initiation sites by fractographic analysis. The Charpy ductile-brittle transition temperatures （DBTT） have been predicted using standard literature equations, and compared to the measured values. The relationship between the ferrite grain size and coarse TiN particle size and number density in terms of whether the coarse TiN particles act as effective cleavage initiation sites is discussed in this paper.展开更多
本文主要针对日本的JIS标准、美国的ASTM标准和中国的GB标准中的冲击试验方法进行比较,列举了它们之间的差异。并结合国标GB/T229冲击试验方法对40Cr Ni Mo A和TC4等两种材料进行了试验研究。结果表明:依据国标GB/T229的方法确定了40Cr ...本文主要针对日本的JIS标准、美国的ASTM标准和中国的GB标准中的冲击试验方法进行比较,列举了它们之间的差异。并结合国标GB/T229冲击试验方法对40Cr Ni Mo A和TC4等两种材料进行了试验研究。结果表明:依据国标GB/T229的方法确定了40Cr Ni Mo A韧脆转变温度为-20℃;而钛合金TC4所得出的试验数据存在着波动,主要和试样的尺寸差异以及表面光洁度有关,其试验结果都符合生产用要求。展开更多
文摘The toughness of ferritic steels is influenced by the grain size distribution, second phase, precipitates and coarse inclusions. In this work an examination of the effect of coarse TiN particles （〉0.5 μm） and ferrite grain size on the Charpy impact transition temperature in high strength low alloyed steels has been carried out. Steels with high Ti content （up to 0.045 wt%）, have been heat-treated and furnace cooled to obtain a ferrite-pearlite microstructure with different ferrite grain sizes. Coarse TiN particle size and ferrite grain size distributions have been measured and Charpy impact testing has been carried out. Scanning electron microscopy （SEM） analysis has been used to measure the grain boundary carbide thickness and to determine if the coarse TiN particles are acting as cleavage initiation sites by fractographic analysis. The Charpy ductile-brittle transition temperatures （DBTT） have been predicted using standard literature equations, and compared to the measured values. The relationship between the ferrite grain size and coarse TiN particle size and number density in terms of whether the coarse TiN particles act as effective cleavage initiation sites is discussed in this paper.
文摘本文主要针对日本的JIS标准、美国的ASTM标准和中国的GB标准中的冲击试验方法进行比较,列举了它们之间的差异。并结合国标GB/T229冲击试验方法对40Cr Ni Mo A和TC4等两种材料进行了试验研究。结果表明:依据国标GB/T229的方法确定了40Cr Ni Mo A韧脆转变温度为-20℃;而钛合金TC4所得出的试验数据存在着波动,主要和试样的尺寸差异以及表面光洁度有关,其试验结果都符合生产用要求。
