所属分类：行业资讯 发布时间：2021-02-02 11:50:04 来源：http://www.lcnmb500.com 浏览量：
HARDOX500耐磨板工厂指出，在片状珠光体形成过程中，片层相间的许多渗碳体与铁素体并非均需通过各自重新 生核形成，研究表明，当铁素体在相渗碳体片两侧产生之后，渗碳体或铁素体的继续交替形成，则可能分别在各自的层片边缘以“搭桥”方式增殖，而勿需重新 生核。珠光体组织中所呈现的渗碳体分枝连接形态，即可证实上述搭桥生长机制。
HARDOX500wear-resistant plate factory pointed out that during the formation of lamellar pearlite, many cementite and ferrite between lamellar phases do not need to be reconstituted by themselves The results show that when the ferrite is formed on both sides of the cementite sheet, the cementite or ferrite will continue to form alternately, and then they may proliferate in the way of "bridging" at the edge of the respective lamellae respectively without re nucleation. The morphology of cementite branching and connecting in pearlite can confirm the above bridging growth mechanism.
The lamellar pearlite of HARDOX500wear-resistant plate is formed by homogenizing austenite under slow cooling condition. The lamellar mixed structure of cementite and ferrite can be clearly observed by optical microscope, and the lamellar spacing is about 15o-450nm. With the increase of undercooling, the morphology of the transition products also changes with the increase of nucleation rate and growth rate. With the decrease of transformation temperature, the cementite and ferrite flakes become thinner, that is, sorbite and troostite.
The granular pearlite system of wear-resistant plate refers to the two-phase mixed structure of cementite which is basically distributed in ferrite. In this paper, the formation of granular pearlite is briefly described in combination with the ordinary spheroidizing annealing process of wear-resistant plate.
Hardox500耐磨板工厂研究表明，在奥氏体转变为珠光体的过程中，奥氏体化温度对渗碳体的形态具有重要作用。当加热温度时，由于奥氏体成分的不均匀性将有助于缓冷时共析渗碳体的球化；相反，随着加热温度增 高，奥氏体均匀化程度增加，则冷 却时形成片状珠光体的倾向增加。
The research in hardox500 wear resistant plate factory shows that the austenitizing temperature plays an important role in the transformation of austenite to pearlite. On the contrary, with the increase of heating temperature, the degree of austenite homogenization increases, and the tendency to form flake pearlite increases.
When austenitizing on the wear-resistant plate, due to the existence of a large number of undissolved carbonized material points, the carbon atoms around them will continue to segregate and spheroidize with these carbonized material points as the core by diffusion during cooling. At the same time, the basic carbon poor zone will contribute to the nucleation and growth of ferrite. Therefore, in the process of forming granular pearlite, the existence of undissolved secondary carbide actually plays the role of spheroidizing core.
The factory test of wear-resistant plate shows that the heating temperature should be reduced appropriately in order to keep the inhomogeneity of austenite composition and facilitate the formation of granular pearlite when the original structure dispersion is large. In addition, heating speed and holding time after heating also have a certain influence. For example, under normal conditions, the spheroidizing annealing temperature of wear-resistant plate is generally 790-810 ℃, while when the rapid heating temperature is 305 ℃, the heating temperature can be increased to 850 ℃.
The dispersion of granular pearlite in HARDOX500耐磨板wear-resistant plate can be directly expressed by the average diameter (or average spacing) of carbide particles and the average number of carbide particles per unit area, which is usually indirectly reflected by the annealing hardness in production.
The dispersity of granular pearlite mainly depends on the heating temperature, the size and quantity of undissolved carbides, and the following isothermal temperature and the cooling rate of continuous annealing also have a certain influence on isothermal annealing. The relationship between the isothermal transformation temperature and the average diameter of carbides and the annealing hardness of wear-resistant plate during isothermal annealing is studied.