退火温度对NM360耐磨钢堆焊层组织与性能的影响

Effect of Annealing Temperature on Microstructure and Properties of Wear-Resistant Steel NM360 Hardfacing Layer

利用D507MoNb焊条对NM360耐磨钢板进行堆焊修复,并于焊后分别在200,400,600℃进行退火处理,研究了退火温度对堆焊层显微组织、硬度、冲击韧性及耐磨性能的影响。结果表明:堆焊层退火前的组织为马氏体+碳化物,在200,400,600℃退火后,堆焊层的组织分别为回火马氏体、回火屈氏体及回火索氏体;随着退火温度升高,堆焊层的硬度降低,冲击韧性增加,耐磨性下降;200℃退火后的堆焊层具有最佳的耐磨性,其相对耐磨性为母材的1.327倍。

NM360wear resistant steel plate was repaired by hardfacing with D507 MoNb electrode and then annealed at different temperature（200 ℃,400 ℃ and 600 ℃）after welding.The effects of annealing temperature on the microstructure,hardness,impact toughness and wear resistance of the hardfacing layer were studied.The results show that the microstructure of the hardfacing layer before annealing was martensite and carbide,after annealing at 200 ℃,400 ℃ and 600 ℃,the microstructure was tempered martensite,tempered troostite and tempered sorbite respectively.With the increase of annealing temperature,the hardness and wear resistance of the hardfacing layer decreased,but the impact toughness increased.The hardfacing layer annealed at 200 ℃ had the best wear resistance,and its relative wear resistance was 1.327 times of the base metal.