Heat treatment process for x12crmowvnbn10-1-1 grain refinement

Abstract

The invention provides a heat treatment process for X12CrMoWVNbN10-1-1 grain refinement, which reduces the amount of acicular austenite as much as possible and increases the amount of spherical austenite by increasing the heating rate, thereby making the grain refinement and making the grain The particle size meets the technical requirements, which expands the application range of X12CrMoWVNbN10‑1‑1. The blanked material is forged to form a workpiece, and then the workpiece is subjected to high-temperature normalizing, high-temperature tempering, conventional normalizing, and high-temperature tempering in sequence, and then the workpiece after high-temperature tempering is subjected to subsequent processing. During the high-temperature normalizing process, the heating rate of the workpiece in the α+γ dual-phase region is increased, so that the workpiece quickly passes through the dual-phase region and obtains as much spherical austenite as possible. On the one hand, it breaks the crystal orientation relationship to a greater extent. , that is, the K-S relationship; on the other hand, increasing the heating rate can increase the nucleation rate of austenite; the specific process of high-temperature tempering is to keep the temperature at 700 ° C for 15-20 hours, so that the carbides can be as much as possible Precipitate, further destroy the relationship of metal orientation, and then air cool.

Description

technical field [0001] The invention relates to the technical field of material heat treatment, in particular to a heat treatment process for X12CrMoWVNbN10-1-1 grain refinement. Background technique [0002] The forging manufacturing industry is the basic industry of the national equipment manufacturing industry. It is also an indispensable strategic industry related to national security and the lifeline of the national economy. It is also an important component of national capabilities. The development level of large forgings is a measure of a country's comprehensive capabilities important sign. [0003] With the rapid development of electric power, petrochemical and other industries at home and abroad, some new technologies and equipment have appeared, and some new materials have been used; at the same time, new requirements have been put forward for the forging industry, which not only promotes the continuous upgrading of forging equipment , and accelerated the generati...

AI Technical Summary

Problems solved by technology

However, due to the high content of alloying elements and a variety of strong carbide-forming elements, this material has very good hardenability and very stubborn structure inheritance. Therefore, after the grain is coarse, the grain size is difficult to refine, and the grain The difficulty of grain refinement is obviously more than that of martensitic heat-resistant steel such as SA336F91 and SA336F92

[0008] The existing heat treatment process for grain refinement of X12CrMoWVNbN10-1-1 steel is normalizing + high temperature tempering, high temperature normalizing + high temperature tempering, and then conventional normalizing + high temperature tempering, complete annealing, the effect is very poor , the grain size can only be increased by 0.5 grades, and the grain size is coarse, the grain boundary area is reduced, and the concentration of carbides and nitrides is relatively increased, thereby increasing the sensitivity to temper brittleness; The path is relatively straight and simple, which reduces the energy absorption and has a significant impact on the impact absorption energy. At present, there is no effective solution. Therefore, to solve the problem of grain size coarsening of X12CrMoWVNbN10-1-1 steel forgings becomes an imminent subject