周继扬
,
W.SCHMITZ
,
S.ENGLER
金属学报
本文用彩色金相法研究了球墨外围奥氏体壳的生长过程及奥氏体对石墨畸变的影响。结果表明,球墨外围的奥氏体壳不是连续的奥氏体层,而是由若干个楔形晶体组成。由于球墨外围奥氏体成核的有利条件不同;故在不同位置先后成核并生长。之后,互相接触形成一个壳。 经电子探针分析,沟槽中正偏析元素及低熔点金属含量高,因而沟槽液体的熔点低、凝固慢。根据沟槽的凝固速度,奥氏体壳可分成快封闭、慢封闭及不封闭三种类型,与石墨球的畸变有密切关系。
关键词:
球墨
,
color metellography
,
austenite
,
deterioration of graphite
梁高飞
,
朱丽业
,
王成全
,
P.Nolli
,
吴建春
,
于艳
,
方园
金属学报
利用Confocal激光扫描显微镜原位观察了AISI304不锈钢冷却加热过程中高温铁素体（δ）→奥氏体（γ）相变的过程及其特征。结果表明，γ相优先在δ晶界处形成；冷却速率影响γ相的生长形态，典型形态分为多边形、块状、圆形、树枝状、板状、网状、以及葫芦状等七种；“游离”γ枝晶发生粗化，并可能和周围的γ枝晶聚合；相同冷却条件下，δ晶界处的γ枝晶聚合程度明显高于δ晶粒内部；二次枝晶在冷却过程中粗化，并竞争生长。冷却速率增大时，伴随着温度的突然先升后降，γ相生长界面失稳，枝晶前端推进速率提高。
关键词:
AISI304不锈钢
,
δ-ferrite
,
austenite
,
phase transformation
,
in-situ observation
Yu CHEN
材料科学技术（英）
A new type of hot-rolled transformation induced plasticity (TRIP) steel with 2.3%Al was developed to replace conventional Si-bearing TRIP steel to improve surface quality of the steel sheet. The relationship between retained austenite volume fraction and hot-rolling processing was researched by Gleeble-2000 thermo-dynamic test for the Al-bearing steel. The experimental result showed that aluminum played an important role on retaining austenite and the volume fraction increased from 4.4% to 7.5% as coiling temperature increased from 350℃ to 450℃, while coiling temperature had a stronger effect on retaining austenite than finishing rolling temperature.
关键词:
Aluminum
,
retained
,
austenite
,
coiling
,
temp
WANG Huaming Institute of Metal Research
,
Academia Sinica
,
Shenyang
,
ChinaZHANG Qing Central Iron and Steel Research Institute
,
Ministry of Metallurgical Industry
,
Beijing
,
ChinaSHAO Hesheng Beijing Graduate School
,
China University of Mining and Technology
,
Beijing
,
China Institute of Metal Research
,
Academia Sinica
,
Shenyang 110015
,
China
金属学报(英文版)
The role of austenite in impact-abrasion process was studied on the basis of the impact-abrasion test results of a newly developed austenite-bainitic ferrite dual-phase abrasion-resistant steel with high strength,high toughness and high strain-hardening ability. It is found that the morphology,distribution and mechanical stability,rather than the volume fraction,of austenite govern the impact abrasion behaviour.Only the appropriate amount of fine and evenly dispersed austenite with adequate mechanical stability in high strength matrices,contribute effectively to the irnpact-abrasion resistance of the materials.While large quantity of coarse austenite with poor mechanical stability,especially when it acted as a continuous matrix of the material,is extremely detrimental to impact-abrasion resistance.
关键词:
austenite
,
null
,
null
,
null
王华明
,
张清
,
邵荷生
金属学报
本文在新型高强韧性奥氏体-贝氏铁素体高碳低合金钢冲击磨料磨损试验结果基础上,讨论了奥氏体在冲击磨损过程中的作用。发现只有在具有一定韧性的高强度基体组织中一定量高度分散分布的稳定性较高的奥氏体,才对抗冲击磨损有利,而组织中大量粗大的机械稳定性较低的奥氏体,尤其是作为连续基体存在时,对冲击磨损抗力极为有害。
关键词:
奥氏体
,
wear resistance
,
austenite
金属学报(英文版)
Thispaperdealswiththephasetransformationofaustenitetoferritewithinthecriticaltemperatureregion(betweenAc1andAc3).Theresultsshowthatthevolumefractionoftransformationofferriteformedisothermallyfromausteniteismainlyvariedwiththeaustenitizingtemperature.Thehighertheaustenitizingtemperature,themorevolumefractionoftheferriteformedisothermallyfromaustenite.Besides,thephasetransformationofaustenitetoferritewithinthecriticaltemperatureregionwascheckedbyaustenitizingisothermaltime.Thevolumefractionofferriteformedisothermallyfromaustenitewithinthecriticaltemperatureregionfordifferentisothermaltimehasheenexaminedexperimentally.Thelglg(l-fv)-1vslgtrelationdoesnotfollowtheAvramiequationstrictlyandconsistsoftwostraightlines.
关键词:
:critical temperature region
,
null
,
null
,
null
,
null
A.G. Huang
,
Y.S. Wang
,
Z.Y. Li
,
J.G. Xiong
,
Q. Hu
金属学报(英文版)
The size of austenite grain has significant e®ects on components and proportions of
various ferrites in low-alloy steel weld metal. Therefore, it is important to determine
the size of austenite grain in the weld metal. In this paper, a model based upon the
carbon diffusion rate is developed for computing austenite grain size in low-alloy steel
weld metal during continuous cooling. The model takes into account the effects of the
weld thermal cycles, inclusion particles and various alloy elements on the austenite
grain growth. The calculating results agree reasonably with those reported experimental
observations. The model demonstrates a significant promise to understand the weld
microstructure and properties based on the welding science.
关键词:
low-alloy steel
,
null
,
null
,
null
