합금 5251 마그네슘이 낮은 Al-Mg계에 속하며 열처리로 강화할 수 없음. 그것에는 좋은 내식성이 있습니다, 용접성, 중간 강도 및 우수한 가소성, 가공 및 성형이 용이합니다..

외국에서, 5251 알루미늄 합금 sheets with different heat treatment states are the main materials used in automobile manufacturing, 통조림 산업 및 기타 분야; in China, so far, the complete technical data of 5251 aluminum alloy H2n and 0-state sheets have not been formed, and their production The process technology has not been formed, and the alloy sheet is not much produced in China.

Combining with market demand and production practice, we study the influence of annealing temperature and holding time on the microstructure and properties of 5251 aluminum alloy sheet after medium temperature rolling, determine the production process and heat treatment system of its H2n and 0 states, and produce aluminum alloys that meet the EN485 standard. plate.

Ⅰ Test scheme 1.1 Test material test A 5251 aluminum alloy ingot with a cross-sectional dimension of 255mmx1500rnm produced by semi-continuous water-cooling casting method is selected, and its chemical composition meets the requirements of Table 1. Table 15251 aluminum alloy chemical composition (질량 분율) % other impurities Si Fe Cu Mn Mg Cr Zn Ti individual total 0.40.50.150.1~0.51.7~2.40.150.150.150.050.15 In 5251 알루미늄 합금, training (마그네슘) Between 1.7% 그리고 2.4%.

Magnesium is the main strengthening element, which exists in the form of solid solution and |3 phase, and plays a certain role in solid solution strengthening. The solid solubility of magnesium in aluminum is 17.4% at 450cC and 1.9% at 100aC. Although the solubility of magnesium in the alloy decreases rapidly with the decrease of temperature, the aging strengthening effect of the alloy is low due to the difficulty in nucleation of the precipitation phase, the few cores and the large precipitation particles. Magnesium enhances the work hardening sensitivity of aluminum, and the alloy can obtain obvious strain strengthening. Manganese and chromium play a supplementary strengthening role.