鋼中含氫所引起的内耗峯

钢的内部发裂已经公认为与钢中的氢气有关。现有的理论认为这是由于氢气聚集于钢中的内部缺陷产生破裂压力所引起,然而关于缺陷的性质和引起内部发裂的详细机构迄今还没有明确的了解。本文尝试用内耗测量的方法来研究这个问题。初步实验的结果指出:(1)氢在钢中可以引起内耗峰(将内耗表示为测量温度的函数时);(2)轻微冷加工或保温对于内耗峰的颠值温度有着显著的影响,这表示所得的内耗峰与钢中的缺陷和应力状态有关系;(3)所得的内耗峰表现有反常的振幅效应,即在一定的观测温度时,如将内耗表示为外加应力的函数,则也得到一个内耗峰。这与本文作者之一以前在铝铜合金中所观测到的反常内耗峰的性质和表现相同,因而所得的内耗峰可能是由于氢与钢中的原子脱节的交互作用所引起来的。

INTERNAL FRICTION PEAK ASSOCIATED WITH THE PRESENCE OF HYDROGEN IN STEEL

Hair-line cracks or flakes in steel are known to be associated with the presence of hydrogen. A prevailing theory states that the crack formation is due to disruptive hydrogen pressure being built up in defects in steel. However, little was known regarding to the nature of these defects and the detailed mechanism of the hair-line crack formation. An attempt was made in the present research to investigate this problem by means of internal friction measurements. The preliminary experiments show: (1) The presence of hydrogen in certain steels may give rise to the appearance of an internal friction peak when internal friction is plotted against the temperature of measurement; (2) a slight amount of cold-work or soaking at a given temperature has a considerable effect on the optimum temperature of the observed internal friction peak, which indicates that the internal friction peak may be connected with the defects or stress condition in steel; (3) the internal friction peak shows an anomalous amplitude effect, i.e., at a given temperature of measurement an internal friction peak is obtained when the internal friction is plotted against the stress amplitude. Such an anomalous behavior is similar to that previously observed by. one of the authors (Ke) in the case of aluminimum containing 0.5% Cu. It is therefore considered that the internal friction peaks observed may be related to the interaction of hydrogen with the dislocations in steel.