摘要
以自升式海洋平台桩腿齿条用177.8 mm厚A514Gr QModified钢板为研究对象,分析了不同调质工艺对实验钢组织和力学性能的影响。实验显示：在900℃一次淬火工艺制度下,板厚1/2处组织主要是粗大的粒状贝氏体及少量马氏体,晶粒度4-5级,回火难以获得良好的强韧性匹配;在930℃＋900℃二次循环淬火工艺制度下,板厚1/2处马氏体所占比例超过80%,晶粒度达到6级以上,后续辅以650℃回火处理,齿条钢板的强韧性获得良好匹配。研究表明：钢板增加一次高温淬火,可固溶较多的合金元素,同时得到内部缺陷较多的初始非平衡组织,为二次淬火加热奥氏体化提供形核动力,提高奥氏体形核率,细化初始晶粒,并且改善钢板淬透性。
Taking 177. 8 mm thickness A514 Gr QModified steel plate for gear rack of jack- up offshore platform leg as research object,the article analyzes the effect of various quenching and tempering processes on microstructure and mechanical properties of experimental steel. The experiment results show that after primary quenching at 900 ℃,coarse granular bainite and less martensite mainly exist at the position of 1 /2 plate thickness with grain size rating of 4- 5 and it is hardly to get good matching of strength and toughness by tempering. After double cycled quenching at 930℃ and 900 ℃,the proportion of martensite at the position of 1 /2 plate thickness amounts to more than 80% with grain size rating over 6,after which A514 Gr QModified steel plate for gear rack receives good matching of strength and toughness by subsequent tempering at 650 ℃. The research results show that one more high temperature tempering on steel plate facilitates more solid solutes of alloying elements,results in initial non- balanced microstructure with more internal imperfections,enables nucleation during austenization of secondary quenching,increases the nucleation rate of austenization,refines the initial grain and improves the hardenability of steel plate.
出处
《宽厚板》
2016年第2期1-4,共4页
Wide and Heavy Plate
