UCON A型水溶性淬火介质在粉末冶金件感应淬火中的应用

Application of UCON A Water-Soluble Quenchant in Induction Quenching of Powder Metallurgy Steel Parts

为减少由铁基粉末冶金制造的汽车链轮在感应淬火时开裂，采用UCONA型水溶性聚合物作为淬火介质。结果表明，UCONA型淬火介质在喷射冷却时不但不产生泡沫，还可以通过对介质浓度的调整，保证淬火介质在过冷奥氏体稳定性最低的温度范围内具有很高的冷却速度，又能显著减缓淬火介质在200～300℃范围内的冷却速度。在链轮硬度与有效硬化层深度达到技术要求的情况下，UCONA型水溶性淬火介质使铁基粉末冶金链轮感应淬火冷却时的应力降到最小，从而把淬火开裂比例控制在1％以内。

In order to reduce the crack during induction quenching of powder metallurgy steel sprockets of car, UCON A water-soluble polymer was used as quenchant. The results show that UCON A PAG quenchant not only removes the scum during spraying cooling, but also ensures very high cooling rate at the temperature range in which the over-cooling austenite＇s stability is the lowest, and decreases remarkably the cooling rate in the region of 200～300 ℃ through adjusting the quenchant concentration. On condition that the sprocket＇s hardness and effective hardening case depth meets the technical requirements, UCON A quenchant can minimize the PM sprocket＇s induction quenching stress, and hence control the quenching crack rate within 1%.