Ni9钢微观结构的TEM研究

TEM STUDY OF MICROSTRUCTURES OF STEEL Ni9

利用ＴＥＭ研究了Ｎｉ９钢中马氏体与奥氏体的微观结构。结果表明，多数回火奥氏体不是严格地按Ｋ－Ｓ或Ｎ－Ｗ关系析出，而是在这两种取向附近变化：在同一马氏体束内，奥氏体可按上述近似关系的不同变体析出；回火奥氏体主药第马氏体晶界析出，呈板条状，惯习面为（３３５）（γ＇）∥（３４１）α，奥氏体向马氏体转变时易形成马氏体孪晶。

The microstructures of martensite and austenite in steel Ni9 treated under 800℃1 h, WQ+670℃1 h, WQ+585℃1 h, WQ were investegated with TEM. Most of tempered austenite particles do not precipetate according to theoritical K-S or N-W orientation relationship (OR) with martensite martrix, but have small deviation from these two ORs. In a martensite lath packet, the different austenite variants with the above approximate ORs are pricipetalted. The lath-like tempered austenite precipetates along martensite boundaries with habit plane (335)γ'∥(341)α. Martensite twins form when austenite transformed into martensite. These twins disappear during tempering.