亚临界热处理对40SiMnCrNiMo高强度钎钢组织和性能的影响

Effect of Subcritical Treatment on Structure and Properties of High Strength Steel 40SiMnCrNiMo for Rock Drill Tools

为简化40SiMnCrNiMo钢钎具的热处理工艺,试验了880℃30min油冷+600℃60min空冷的调质处理,860℃30min空冷的正火和780℃30min空冷的两相区亚临界热处理后钢的组织和性能。结果表明,亚临界热处理后钢中贝氏体区HV显微硬度值低于正火钢,钢的V-型冲击功为30J,高于正火后钢V-型冲击功(12J),接近调质后的V-型冲击功(40J)。钎杆寿命试验得出,正火钢钎具平均钻孔进尺10.78m,亚临界热处理钢钎具平均钻孔进尺108.30m,可满足使用要求和替代调质处理钎杆。

The structure and properties of steel with three kinds heat treatment processes - quenched at 880 ℃ for 30 min oil eooling ＋ tempered at 600 ℃ for 60 min air eooling, normalized at 860 ℃ for 30 min air eooling and two-phase region subefitieal treated at 780 ℃ for 30 min air eooling, in order to get a simplified heat treatment proeess of 40SiMnCrNiMo for rock drill tools. The results showed that the HV mierohardness value at bainite region of suberitieal heat treated steel lowed than that of normalized steel and V-notehed impaet energy was 30 J higher than that of normalized steel （ 12 J） and approaehed to that of quenehed and tempered steel （40 J）. The test for service life of rock drill tools indieated that as eompared with average 10. 78 m drill paee of advanee of normalized steel tool, the average drill paee of advanee of suberitieal treated steel tools was 108.30 m to meet the requirement of use and to be available to replaee quenehed and tempered drill tools.