湖南大学学报（自然科学版）2016，Vol.43Issue(12)：1-10,10.
气体渗氮及后续回火工艺对2Cr13钢渗氮层的影响∗
Effect of Gas Nitriding and Subsequent Tempering on Nitrided Layer of 2Cr1 3 Steel
摘要
Abstract
The effect of gas nitriding and subsequent ageing on the microstructure and properties of 2Cr13 steel was investigated using X-ray diffractometer,scanning electron microscope,transmission elec-tron microscope,microhardness tester,wear tester,bend test and immersion corrosion test.It was found that with the increase of nitriding temperature and time,both of the thickness of nitrided layers and sur-face porous layer increased.The diffusion layers of the sample nitrided at 500 ℃ mainly consisted of mar-tensite,a large amount of dislocation and dislocation cell structure,as well as a large amount of CrN nano-precipitates.The CrN nano-precipitates dispersedly distributed in the interior of grains and at the bounda-ries of dislocation cells,and the CrN nano-precipitates at the boundaries of dislocation cell were denser andlarger than those in the grain interior.Further,a large amount ofε-Fe2-3 N or (Cr,Fe)2 N were precipita-ted in the grain boundaries of lath martensite.When the nitriding temperature increased up to 550 ℃,the martensite recovered itself,and the CrN precipitates lined up to form CrN lamellas.The microstructure of the diffusion layers was also transformed into the lamellar pearlite that consists of theα-Fe matrix and CrN phase.The surface hardness of nitrided samples first increased and then declined with the increase of nitri-ding temperature,where the peak hardness (1 274 HV0.5 )reached at 500 ℃.On the other hand,the hard-ness of diffusion layers formed between 450 ℃ and 500 ℃ was greater than 1 300 HV0.1 ,and obviously de-creased with the nitriding temperature.The wear resistance and corrosion resistance of 2Cr13 steel were improved after nitriding at 500 ℃ for 5 h,but the bend toughness decreased.No matter water cooling or air cooling or subsequent tempering of 420 ℃ for 2 h was applied,the variance of the microstructure at the diffusion layers of 2Cr13 steel nitrided at 500 ℃ was limited,and their hardness was also not changed obvi-ously and was still greater than 1 000 HV0.1 .关键词
2Cr13 钢/气体渗氮/硬度/CrN析出相/微观组织结构Key words
2Cr13 steel/gas nitriding/hardness/CrN precipitates/microstructure分类
矿业与冶金引用本文复制引用
伍翠兰,陈兴岩,王津,洪悦,田磊..气体渗氮及后续回火工艺对2Cr13钢渗氮层的影响∗[J].湖南大学学报（自然科学版）,2016,43(12):1-10,10.基金项目
国家自然科学基金资助项目(51071064,51371081),National Natural Science Foundation of China(51071064,51371081) （51071064,51371081）
