相间沉淀钢的组织与性能

RELATIONSNIPS BETWEBN MICRO8TRUCTURE AND MECNANICAL PROPERTIES IN A NEW INTERPHASE PRECIPITATION STEEL

本文研究了一种新型的相间沉淀钢。试验结果表明：在奥氏体直接分解过程中，单纯用ＶＣ产生相间沉淀，很难获得强度与韧性的最佳配合，也难直接在热轧或正火状态下使用。在Ｆｅ－Ｖ－Ｃ基础上添加适当的锰和铝，连续冷却时可使σ＿ｓ＞５５０ＭＰａＣＶＮ（室温）＞１６０Ｊ。对φ２００ｍｍ以下的棒材，空冷时能获得均一的组织与性能。如欲获得更高强度，可藕回火改善韧性。与低碳贝氏体钢比较，在相同强度下有更高的韧性与低的相间沉淀临界冷速。预期有较大的应用前景。本文还详细研究了相间沉淀钢的组织、转变动力学；对强度与韧性的控制因素也作了进一步探讨。

AbstractA new type of interphase precipitation steel has been developed. For simple Fe-V-C alloy,it is difficult to obtain a optimal combination between strength and toughness during the pro-cess of direct decomposition of austenite and it is also impossible to use directly in as-hot rol-led or normalized. Addition of a certain amount of Mn and Al on the basis of Fe-V-C alloy system,the steel reachs following mechanical properties during continuous cooling:σ_s >550 MPa,room charpy value>160J.Uniform structure and properties can be achieved With section larger than 200mm in diameter.Tempering is required to improve toughness if higher strength is desired. When the strength being equal,it has higher,toughness and hardenability of inter-phase precipitation in comparison with low carbon bainite steel.Therefore, it is expected to have a broad prospect.The paper also gives a more detail in structure and transformation ki-netics.The faotors that control strength and toughness are further explored.