焊接速度对18-8不锈钢堆焊层组织形态的影响

Influence of welding speed on morphology of 18-8 stainless steel cladding layer

采用带极电渣焊方法在Q235表面得到了18-8不锈钢堆焊层。研究不同焊接速度对18-8不锈钢堆焊层组织形态的影响。结果表明,带极电渣堆焊层显微组织主要由奥氏体和少量δ铁素体构成,其中δ铁素体有断续状(或称蠕虫状)、骨架状和板条状三种形态,决定于堆焊层的合金成分、焊接热输入及冷却条件等因素。当焊速过小时,堆焊层组织中δ铁素体的形态主要是断续状和骨架状;当焊速过大时,δ铁素体的形态主要是板条状和骨架状;当焊速适中时,可获得热输入小、稀释率低、成形良好,显微组织为奥氏体基体和骨架状δ铁素体的堆焊层组织。

The cladding of 18-8 stainless steel is prepared on the surface of Q235 by electroslag welding.The influence of varied welding speeds on morphology of cladding layer is researched.The results show that,the microstructure of electroslag cladding is mainly austenite and small amounts of δ -ferrite.Three forms of δ -ferrite ,intermittent ferrite morphology （or worm fertile morphology）, skeleton ferrite morphology and lathy ferrite morphology,is observed.Which form of the δ -ferrite is got depends on alloy components of cladding layer,heat input of welding and the cooling condition etc. When the welding speed is too low,the form of δ ferrite is mainly intermittent morphology and skeleton morphology,when the welding speed is too high,the form of δ ferrite is mainly lathy morphology and skeleton morphology.When the welding speed is moderate,there is a small heat input and a low dilution rate,and get a cladding layer with good welding forming.at the same time,its microstructure is austenitic matrix and skeleton morphology δ ferrite.