通过对大规格SAE4330V-MOD合金钢金矿钻杆进行不同温度的淬火和回火热处理,探讨研究了该合金钢的调质热处理工艺.结果表明:将该钢先加热到650 ℃保温3 h,然后升温至860 ℃保温6 h后淬入不高于70 ℃水中,最后在620 ℃回火6 h后出炉空冷,该钢可获得均匀细小的回火索氏体组织,且抗拉强度、冲击功和硬度等达到最佳匹配,各项力学性能均能满足技术要求;若该钢热处理前的原始组织中存在少量的贝氏体,则会导致其热处理后的力学性能不能满足技术要求,因此热处理前应严格控制该钢的原始显微组织.

Through quenching and tempering the large-section SAE4330V-MOD alloy steel drill pipes used in a gold mine at different temperatures,the heat treatment process of the steel was studied.The results show that by first heating the steel to 650 ℃ and holding for 3 h,then heating to 860 ℃ and holding for 6 h following quenching in less than 70 ℃ water,and finally tempering at 620 ℃ for 6 h,uniform fine tempered sorbite microstructure could be obtained and best match among tensile strength,impact energy and hardness was achieved with various mechanical properties all meeting the technical requirements.If there was small amount of bainite in microstructure of the steel before heat treatment,it would lead the mechanical properties after heat treatment could not meet the requirements.Therefore,original microstructure of the steel should be strictly controlled.