X-射线小角散射法测定钢铁及合金中析出相的粒度

Determination of particle size of precipitate phase in steel and alloy by small angle X-ray scattering method

对钢铁及合金中各种不同粒度析出相的电解提取和化学分离方法、X-射线小角散射法测定析出相粉末的测定条件进行了研究,优选了各种测定参数,从而建立了钢铁及合金中多种析出相粒度分布分析方法。该方法被广泛应用于各种高温合金、中低合金钢、微合金化钢中碳化物、金属间化合物的粒度尺寸分布的测定。结果发现,随着回火温度的增加,低合金钢中的M3C相的数量增加,但粒度变化不大,当回火温度升至700℃时,M3C相分解而使平均粒度增加;在含铬的中低合金钢中,析出的M23C6相的粒度随时效温度的增加而增加,而MC相的粒度无明显变化;在一类高温合金中,800℃时γ′的粒度随时效时间的增加而增加,另一类高温合金富铬相α-Cr的粒度明显要比其他的析出相颗粒要粗,平均粒度达390 nm。

The electrolysis extraction and chemical separation methods for precipitates with different particle size in steel and alloy along with the determination conditions for the particle size of the precipitates by small angle X-ray scattering method have been investigated. The determination parameters were optimized. The present method has been used for the particle size determination of carbides and metal precipitates in microalloyed steel, middle-alloy steel and high-temperature alloys. It was found that in low-alloy steel the amount of M3 C phase increased with the rise of tempering temperature and the mean particle size of M3C phase did not change obviously. When the tempering temperature rised to 700 ℃, M3C phase decomposed and mean particle size increased. For middle-alloy steel containing chromium the mean size of M23 C6 increased and the mean size of MC had no obvious variation with the rise of aging temperature. With the increase of aging time the particle size of γ＇ increased at the tem- perature of 800 ℃ in a tape of nickel base high-temperature alloy. The chromium phase such as α-Cr had larger particle size than other phase in high-temperature alloy and the mean size of α-Cr in the other nickel base high-temperature alloy was 390 nm.