张增志
中国腐蚀与防护学报
褐煤和泥炭遇水后呈现酸性。研究了褐煤和泥炭中羧基和酚羟基对低合金钢27SiMn的腐蚀作用。配制两种煤的水溶液及饱和水煤样作为电化学腐蚀试验介质，测量了介质的pH值。通过测量极化曲线和红外光谱分析了27SiMn在上述介质中的腐蚀机制。结果表明，褐煤中的羧基和酚羟基加速27SiMn的腐蚀，而泥炭中的羧基和酚羟基却对27SiMn的阳极溶解有抑制作用。
关键词:
褐煤
,
peat
,
corrosion
,
low-alloy steel
张恒陈学群常万顺
中国腐蚀与防护学报
选取有代表性冶金元素的几种低碳钢和低合金钢，通过在3%NaCl（pH=10）溶液中的极化实验比较它们之间的点蚀诱发敏感性，用电子探针（EPMA）分析钢中夹杂物诱发点蚀的腐蚀特征。结果表明，脱氧程度较差的沸腾钢的抗点蚀诱发能力明显优于脱氧程度完全的镇静钢，经过稀土处理的镇静钢的抗点蚀诱发能力有所改善，介于两者之间。镍铬系低合金钢的抗点蚀诱发能力优于锰系低合金钢，说明钢中合金元素对点蚀诱发敏感性有重要影响钢中夹杂物是最主要的点蚀诱发源，夹杂物边界钢基体表面的氧化膜最薄弱，夹杂物诱发点蚀的最初腐蚀均始于该基体处。
关键词:
沸腾钢
,
killed steel
,
low-alloy steel
,
pitting
,
inclusion
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
ZHENG Wenlong ZHU Xiying SU Limin Shanghai Research Institute of Materials
,
Shanghai
,
China ZHENG Wenlong
,
Senior Research Engineer
,
Shanghai Research Institute of Materials
,
99 Handan Road
,
Shanghai
,
China
金属学报(英文版)
Fracture behaviour of low-alloy steels AIST4340,HY100,Welten60,AISIA537 and A131 in artificial seawater under static,cyclic loading and at cathodic protection potential has been investigated by using the techniques of fracture mechanics, electrochemistry and electronfractography.The results reveal that at hydrogen evolution potentials(cathodic pro- tection potential)the critical yield strength required for the occurrance of SCC decreases from 985 at corrosion potential(E_c)to 872 MPa.The effect of cathodic protection on crack propagation of corrosion fatigue(CF)is not simple,it is closely related to the yield strength of steels and their SCC behaviour.For the steels with high yield strength,cathodic protection promotes(da/dN)_Ⅱ evidently,and reduces △K_(th) value.The(da/dN)-△K curves dis- play a plateau at the third stage of CF for steels with medium or low yield strength.It is men- tioned that the cathodic protection potential for oceaneering constructures should be control- led at top level of the protective range.It seems reasonable that the strength of steel for oceaneeing use might be increased by 200 or 300 MPa.
关键词:
low-alloy steel
,
null
,
null
,
null
,
null
D.D.Shen
金属学报(英文版)
Grain boundary segregation of phosphorus during tempering at 540℃ after quenching from 980℃ is examined for a P-doped 2.25Cr1Mo steel by means of Auger electron spectroscopy.The solute-boundary binding energy and the diffusion coefficient for phosphorus are determined by virtue of the measured segregation kinetics along with the equilibrium segregation theory.The obtained values of the above parameters are discussed with comparison to those found in the literature for low-alloy steels.
关键词:
segregation
,
null
,
null
马博
,
彭艳
,
刘云飞
,
贾斌
材料热处理学报
采用Gleehle-3500热模拟实验机对低合金钢Q345B进行热压缩实验,研究其在变形温度为900～1100℃和应变速率为0.01～10 s-1条件下的动态再结晶行为.结果表明:低合金钢Q345B在变形过程中存在动态再结晶现象,且随着温度的升高和应变速率的降低,临界应变越小,动态再结晶越易发生.根据流变应力、应变速率和变形温度的相关性,得到了动态再结晶激活能.通过对热模拟实验数据的分析计算,建立了峰值应变模型,动态再结晶临界应变模型和动态再结晶动力学模型.并对动态再结晶动力学模型进行了误差分析,证明了模型具有较高的精确性.最后,通过所建立的模型分析了变形条件对动态再结晶的影响,验证了实验所得出的在高温、低应变速率下更有利于动态再结晶发生的规律.
关键词:
Gleeble-3500
,
低合金钢
,
动态再结晶
,
热模拟
,
模型
