The oxidation behavior of B-bearing high-speed steel was studied at 923[Formula: see text]K. The results showed that the as-cast microstructure of 1.0 wt.%B high-speed steel was composed of pearlite + ferrite + M7(C, B)3 + M2(B, C). When the boron content increased, the microstructure gradually changed into martensite + retained austenite + netlike M2(B, C) + M[Formula: see text](C, B)6 + M7(C, B)3. The cyclic oxidation of B-bearing high-speed steel at K followed parabolic rule. The unit area mass gain of 1 wt.%B high-speed steel was 4.2 g/m2 after 923 K/250 h oxidation, and the unit area mass gain of 3 wt.%B high-speed steel was only 3.5 g/m2. The oxidation of boron element formed B2O3, which was mainly enriched at the interface of the oxide film/matrix. B2O3 flowed in the oxide film at high temperature and was easy to fill the defect. B2O3 was easy to form B2O3-SiO2 borosilicate with SiO2. The more boron content was, the more favorable it was to form B2O3-SiO2 borosilicate oxide layer rich in B2O3 and the more favorable it was to spread in the oxide film, so that the oxidation resistance of B-bearing high-speed steel could be remarkably improved.

中文翻译：

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硼含量对含B高速钢高温抗氧化性的影响

在923[公式：见正文]K处研究了含B高速钢的氧化行为。结果表明，1.0 wt.%B高速钢的铸态显微组织由珠光体+铁素体+M组成。7(C, B)3+ 米2(B, C)。当硼含量增加时，显微组织逐渐转变为马氏体+残余奥氏体+网状M2(B, C) + M[公式：见正文](C, B)6+ 米7(C, B)3. 含B高速钢在K处的循环氧化遵循抛物线规律。1 wt.%B高速钢的单位面积增重为4.2 g/m2923 K/250 h氧化后，3 wt.%B高速钢的单位面积增重仅为3.5 g/m2. 硼元素氧化形成B2○3，主要富集在氧化膜/基体的界面处。乙2○3在高温下流入氧化膜，容易填补缺陷。乙2○3很容易形成B2○3-SiO2含 SiO 的硼硅酸盐2. 硼含量越多，越有利于形成B2○3-SiO2富含B的硼硅酸盐氧化物层2○3越有利于在氧化膜中的铺展，使含B高速钢的抗氧化性能显着提高。