【摘要】 研究T8A(80 )钢在真空加热时奥氏体的晶粒长大现象 ,分析该钢在缓慢加热和冷却时在试样表面上石墨的析出与长大过程。研究结果表明 :T8A钢加热温度超过 80 0℃时其奥氏体晶粒就开始长大 ,110 0℃时奥氏体晶粒急剧长大 ,超过 12 0 0℃时奥氏体晶粒长大倾向反而减小 ;T8A钢在真空缓慢加热到 70 0℃左右时开始析出点状石墨 ,加热升温到 80 0℃时石墨析出量显著增多 ;当加热到 90 0℃时 ,析出量反而减少 ;当T8A从 110 0℃冷却到 770℃时石墨开始析出 ,冷却到 76 5～ 76 0℃时 ,析出蝶状石墨 ,冷却到 70 0℃时析出的石墨连成一片 ,析出终止。更多还原

【Abstract】 To research the austenitic grain growth phenomenon of T8A(80) steel heated in vacuum and analyze the precipitation and growth course of graphite on the sample surface when the steel is slowly heated and cooled. The research result shows that when T8A steel is heated to over 800 ℃,its austenitic grains start to grow up; the austenitic grains grow up promptly at 1 100 ℃; the trend of austenitic grain growth decreases adversely over 1 200 ℃. When T8A steel is slowly heated to about 700 ℃, the dot shape graphite begin to precipitate;when heated to 800 ℃,the precipitation of graphite increases obviously; when heated to 900 ℃,the precipitation decreases adversely. When T8A steel is cooled from 1 100 ℃ to 770 ℃,the graphite begin to precipitate;when cooled to 765～760 ℃,the butterfly shape graphite precipitate;when cooled to 700 ℃,the precipitated graphite join together and the precipitation ends.更多还原