论文部分内容阅读
当要求钢材具有很高屈服强度或抗拉强度(200～250kgf/mm~2)时,采用传统的形变热处理方案,即高温形变热处理与低温形变热处理是合适的。但有许多产品,只要达到中等强度,即100kgf/mm~2左右就足够了,对于这种强度水平,只要在奥氏体等温分解为珠光体组织前进行预形变就可保证达到。 如果奥氏体分解前进行热塑性变形,则经这种处理后具有珠光体组织的钢其机械性能可大为改善。这种处理方法称为高温形变等温热处理。 本文目的在于仔细地研究高温形变等温热处理引起的珠光体组织变化,同时通过与常规等温处理对比(奥氏体未经预形变),研究组织变化与钢的机械性能变化之间的关系。
When the requirements of steel with high yield strength or tensile strength (200 ~ 250kgf / mm ~ 2), the use of conventional deformation heat treatment program, that is, high temperature deformation heat treatment and low temperature deformation heat treatment is appropriate. However, for many products, it is sufficient to reach a medium strength of about 100 kgf / mm to about 2, and for this level of strength, pre-deformation can be achieved as long as austenite is isothermally decomposed into pearlite structure. If the austenite is subjected to thermoplastic deformation before decomposition, the mechanical properties of the pearlite-bearing steel after this treatment can be greatly improved. This treatment is called high temperature deformation isothermal treatment. The purpose of this paper is to study carefully the changes in the microstructure of the pearlite caused by the isothermal heat treatment at elevated temperatures and to investigate the relationship between the changes in the structure and the changes in the mechanical properties of the steel by comparison with conventional isothermal treatment (austenitic without pre-deformation).