核电用1cr13厚壁管材内表面裂纹产生原因分析

ANALYSIS OF CRACK FORMATION AT INNER SURFACE OF lCrl3 THICK WALL TUBE APPLIED IN NUCLEAR REACTOR

分析了热轧后空冷产生的淬火效应、退火缓冷引起的回火脆性和轧制对裂纹生长方向的影响.不合理的热处理制度使材料发生马氏体相变和回火脆性,在冲击性冷轧后产生开裂.而轧制压扁造成的内表面切向拉应力是产生纵向裂纹的原因.

Tempering brittleness is an important reason for microcrack formation and cracking in thick wall tube made by steel 1Cr13 which is applied in reactor driving mechanism.This article analysed the quenching effect caused by hot rolling followed by air cooling,tempering brittleness caused by annealing followed by slow cooling,and influence of rolling on the cracking direction.Improper heat treatment condition derives martensite transformation and tempering brittleness,which make the steel cracking when rapidly cold rolling.Tangential tensile stress caused by squashing the tube during rolling is the reason for the formation of longitudinal crack.