热处理保护涂料对D406A钢焊接接头显微组织的影响

Effect of heat treatment with protective coating on microstructure of D406A steel welded joint

采用透射电镜分析了涂料保护调质处理后D406A钢焊接接头的微观组织,用扫描电镜观察了其拉伸断口形貌,并用电子探针分析了热处理保护涂料对基体材料主要合金元素成分的影响。结果表明,采用保护涂料调质处理后未发现涂料中的元素渗入基体,但在焊缝区及热影响区的马氏体板条被细化,板条上析出的碳化物弥散度增加,拉伸断口上韧窝的尺寸减小。

The effects of heat treatment with protective coating on the microstructure and properties of IM06A steel welded joint were investigated through observing microstructure by TEM and fracture appearance by SEM ,and the main alloy elements distribution in matrix by EPM were also analyzed. The results show that after quenched and tempered with pro- tective coating, no elements in the protective coating are found to permeate into the matrix, but the martensite laths in welded zone and heat affected zone are refined and the dispersion of carbides in these area is increased, the sizes of the dimples in these fracture are decreased.