高硼奥氏体钢的抗氧化性能

研究了高硼奥氏体钢在850℃下的高温抗氧化性能,采用SEM研究了材料的组织状态。结果表明,不含硼的奥氏体耐热钢850℃保温9 h和20 h的抗氧化评级均为GB/T 13303-1991中的4级“弱抗氧化性”,材料抗高温氧化性能优于ESR-H13的5级“不抗氧化性”。添加硼后,氧化过程中硼有利于形成致密的氧化薄膜CrBO3,有效阻止了氧化行为的深入,提高了材料的抗氧化性能。含硼0.3%、碳0.5%的奥氏体耐热钢850℃保温9 h和20 h抗氧化评级均达到2级“抗氧化性”。高硼奥氏体耐热钢的含碳量从0.2%提高到0.4%时,材料均具备良好的抗氧化性能,850℃下保温9 h和20 h的氧化速度均达到2级“抗氧化性”标准。较高的含碳量提高了奥氏体基体稳定性,并有利于形成CrBO3。高硼奥氏体钢的高温抗氧化性能优于ESR-H13钢。

High-Temperature Oxidation Resistance Properties of High-Boron Austenitic Steels

The high-temperature oxidation resistance properties of high-boron austenite steels(HBASs)at 850℃were studied.The microstructure of the material was studied by SEM.The results show that the antioxidant rating of boron-free austenitic heat resisting steel at 850℃for 9 h and 20 h is“weak antioxidant”of grade 4 in GB/T 13303-1991,and the materials oxidation resistance at high temperature is better than that of grade 5“non-antioxidant”of ESR-H13.After the addition of boron,boron is conducive to the formation of dense oxide film CrBO3 during the oxidation process,which effectively prevents the further oxidation and improves the antioxidant properties of the materials.The austenitic heat resistant steel containing boron 0.3%and carbon 0.5%reach the antioxidant rating of grade 2“antioxidant”at 850℃for 9 h and 20 h.When the carbon content of high boron austenitic heat resistant steel increases from 0.2%to 0.4%,the material has good antioxidant properties,and the oxidation rates of 9 h and 20 h under 850℃reach the level 2“antioxidant”standard.The higher carbon content improves the stability of austenite matrix and facilitates the formation of CrBO3.The high boron austenitic steel has better oxidation resistance than ESR-H13 steel.