30CrMnSiNi2A钢焊接HAZ的组织对氢行为和性能的影响

EFFECT OF HAZ STRUCTURE FORMED IN WELDING 30CrMnSiNi2A STEEL ON BEHAVIOR OF HYDROGEN AND OTHER PROPERTIES

摘要:

本文用透射电镜,阴极电解法和定载延迟试验等方法,通过对30CrMnSiNi2A超高强钢模拟HAZ组织结构对氢扩散行为和性能影响的考察,研究了三种HAZ组织的吸氢规律、三种HAZ过热区组织中氢的扩散系数和溶解度,经冷处理后组织中氢扩散行为的变化,以及这些组织的氢裂敏感性。试验结果表明:过热区组织状态的改善是后热HAZ性能显著提高的根本原因。以薄膜状分布于马氏体板条间的残余奥氏体,由于其对扩形氢的特殊作用和优良的韧性,对HAZ性能的提高起了重要作用。

Abstract:

This paper deals with the rules of hydrogen absorption of three types of HAZ structure formed in welding 30CrMnSiNi2A ultra-high strength steel,including the related diffusion coefficient and solubility of hydrogen in the overheated region of HAZ,the changes on the behavior of hydrogen diffusion after subzero treatment,and the sensitivity of the structues to hydrogen embrittlement.The authors investigated the influence of the simulated structure of the HAZ on the behavier of hydrogen diffusion by using the methods of transmission electron microscope,cathodic electrolysis and definite load delaycd fracture test.It has been noted that the improvment in structure of the overheated region is the essential condition for the improvoment in proporty of the post-heated HAZ.The filmlike retained austenite spread over between the martensite lath packets plays an important role in raising the proporty of HAZ.