论文部分内容阅读
采用阴极充H和H热分析等实验方法,研究了新开发的1500MPa级高强度钢42CrMoVNb在不同奥氏体化温度淬火和不同温度回火后的H吸附行为,并与常用钢42CrMo进行了对比.结果表明,在淬火态及不同温度回火处理后,42CrMoVNb钢充H试样的H逸出曲线峰值温度θ_P200—250℃之间.回火温度从200℃升高到500℃时,充H试样的H含量缓慢增加;当回火温度升高到500℃以上时,充H试样的H含量急剧增加,并且在600℃附近达到最高值6.6×10~(-6)左右,该H含量约为淬火态时的5倍;继续提高回火温度,则H含量又急剧下降.在不同奥氏体化温度(850—1100℃)加热淬火,经400℃回火时,没有细小弥散的(V,X)C碳化物析出,因而充H试样的H含量随奥氏体化温度升高的变化不明显;而在有细小(V,X)C析出的峰值温度600℃回火时,H含量则随奥氏体化温度的升高而明显增加.这表明,细小弥散的(V,X)C碳化物可作为H陷阱而吸附大量的H.通过改变升温速率测定(V,X)C析出相的H陷阱激活能E_a=28.7kJ/mol.
H adsorption behavior of newly developed 1500MPa high strength steel 42CrMoVNb after quenching at different austenitizing temperatures and tempering at different temperatures was studied by using experimental methods such as cathodic charge H and H thermal analysis. Compared with common steel 42CrMo, .The results show that the peak temperature of H escape curve of 42CrMoVNb steel filled with H after quenching and tempering at different temperatures is between θ_P200 and 250 ℃ and when the tempering temperature is raised from 200 ℃ to 500 ℃, When the tempering temperature was increased above 500 ℃, the content of H in the sample filled with H increased sharply and reached the highest value around 6.6 × 10 ~ (-6) at 600 ℃. The H Content is about 5 times quenching state; continue to raise the tempering temperature, the H content decreased sharply at different austenitizing temperature (850-1100 ℃) heating quenching, 400 ℃ tempering, there is no fine dispersion (V, X) C carbides are precipitated. Therefore, the content of H in the charge H specimen does not change obviously with the increase of the austenitizing temperature. When the peak temperature is 600 ℃ , The H content increases obviously with the increase of the austenitizing temperature.This shows that the finely dispersed (V, X) C carbides can adsorb a large amount of H traps H. Determination of (V, X) C H precipitation phase trap activation energy E_a = 28.7kJ / mol by varying the heating rate.