王长健. Analysis on Surface Crack Formation Mechanism for Crankshaft Forgings of Steel 42CrMo and Process Improvement[J]. Special Steel, 2014, 35(3): 59-61.
王长健. Analysis on Surface Crack Formation Mechanism for Crankshaft Forgings of Steel 42CrMo and Process Improvement[J]. Special Steel, 2014, 35(3): 59-61.DOI:
回火时间不足(4 h)和锻件存在较严重的带状组织(3级)是该曲轴产生淬火裂纹的主要原因。通过将回火时间延长至5 h
控制带状组织≤2级
曲轴调质后未发现裂纹
产品合格率达100%。
Abstract
An analysis on the surface crack formation for crankshaft forgings of steel 42CrMo (/%: 0. 43C
0. 77Mn
0. 24Si
0. 014P
0. 007S
1. 08Cr
0.17Mo
0. 01Cu) with 865 ℃ 1. 5 h oil quenching + 640 ℃ 4 h tempering
water cooling has been carried out. Results show that the surface cracks of crankshaft forgings are quenching cracks
and the main causes for quenching cracks of crankshaft are insufficient tempering holding time (4 h) and more serious banded orientation structure exiting in forgings (rating 3). With prolonging the tempering time to 5 h and controlling the banded orientation structure in forgings ≤ rating 2
the cracks are not found in quenched and tempered crankshaft forgings and the qualified products are up to 100%.