国开行发行3年期债券，规模60亿元，发行利率1.5281%，预期1.5600%，投标倍数3.93倍，边际倍数1.41倍；国开行发行7年期债券，规模20亿元，发行利率1.6860%，预期1.7000%，投标倍数5.10倍，边际倍数5.25倍。

Core Points - The China Development Bank issued a 3-year bond with a scale of 6 billion yuan and an issuance rate of 1.5281%, which was lower than the expected rate of 1.5600% [1] - The bid-to-cover ratio for the 3-year bond was 3.93 times, while the marginal bid-to-cover ratio was 1.41 times [1] - Additionally, the bank issued a 7-year bond with a scale of 2 billion yuan and an issuance rate of 1.6860%, also lower than the expected rate of 1.7000% [1] - The bid-to-cover ratio for the 7-year bond was 5.10 times, with a marginal bid-to-cover ratio of 5.25 times [1]