Comparison of up ladder type and terraced type normalizing heat treatments of heavy cylinder  

作　　者：孙建亮 彭艳 邱丑武 张永振 

机构地区：[1]National Engineering Research Center for Equipment and Technology of Cold Strip Rolling,Yanshan University

出　　处：《Journal of Central South University》2016年第11期2777-2783,共7页中南大学学报（英文版）

基　　金：Project(51305388)supported by the National Natural Science Foundation of China;Project(BJ2014055)supported by the Youth Talent Projects of Colleges in Hebei Province,China;Project(2016M590211)supported by China Postdoctoral Science Foundation

摘　　要：Because of the mixed grain and coarse grain structure, the long heat treatment cycle and large energy conservation in the heavy cylinder heat treatment process, the up ladder type and terraced type normalizing heat treatment of heavy cylinder after rolling were put forward. The microstructure and mechanical properties of 2.25Cr1Mo0.25 V steel after the up ladder type normalizing, terraced type normalizing and isothermal type normalizing were studied. Experimental results show that： 1） For the grain refinement, the twice terraced type normalizing is better than the up ladder type and isothermal type normalizing, and the average grain size is 18 μm; 2） The yield strength, tensile strength and-30℃ charpy impact energy after twice terraced type normalizing are 681 MPa, 768 MPa and 181 J, respectively, and the mechanical properties are better than those of the up ladder type and isothermal type normalizing; 3） Compared with the isothermal type normalizing, the holding time of terraced type normalizing can be shortened by 30%, which greatly reduces the energy consumption.Because of the mixed grain and coarse grain structure, the long heat treatment cycle and large energy conservation in the heavy cylinder heat treatment process, the up ladder type and terraced type normalizing heat treatment of heavy cylinder after rolling were put forward. The microstructure and mechanical properties of 2.25Cr1Mo0.25 V steel after the up ladder type normalizing, terraced type normalizing and isothermal type normalizing were studied. Experimental results show that: 1) For the grain refinement, the twice terraced type normalizing is better than the up ladder type and isothermal type normalizing, and the average grain size is 18 μm; 2) The yield strength, tensile strength and-30 °C charpy impact energy after twice terraced type normalizing are 681 MPa, 768 MPa and 181 J, respectively, and the mechanical properties are better than those of the up ladder type and isothermal type normalizing; 3) Compared with the isothermal type normalizing, the holding time of terraced type normalizing can be shortened by 30%, which greatly reduces the energy consumption.

关 键 词：heavy cylinder terraced type normalizing up ladder type normalizing mechanical properties 

分 类 号：TG156.4[金属学及工艺—热处理]