防止45钢件淬火裂纹的工艺研究

The technological research on preventing 45 steel parts from quenching cracks

45钢件在淬火处理时,易出现淬裂现象.研究表明:4mm～12mm的45钢件在830℃～850℃×1.1min/mm～1.2min/mm的加热和保温条件下,淬入清水或10%的盐水中易出现裂纹.而采取加大工艺预留量(13mm～14mm)、避开危险尺寸(4mm～12mm)、低温(750℃～760℃)淬火、控制加热温度(780℃～790℃)以及保温时间和回火时间等措施,可有效防止45钢件淬火时出现裂纹现象.对于截面尺寸在4mm～12mm的零件,采用低温淬火其淬火合格率>99%.

The 45 steel parts easily come out the quenching crack phenomenon during quenching treatment.The research shows:45 steel parts of 4 mm～12 mm easily appears the quenching cracks in clear water or 10% salt water under the condition of heating at 830 ℃～850 ℃×1.1 min/mm～1.2 min/mm and keeping warm.However it can take some measures to enlarge the technological allowance amount (13 mm～14 mm),avoiding the dangerous dimensions(4 mm～12 mm) by quenching at low temperature (750 ℃～760 ℃),then controlling the temperature (780 ℃～790 ℃) of heating,the time of keeping warm and the time of tempering and so on.All these can be effective to prevent the 45 steel parts from the crack phenomenon as quenching.Regarding the parts of the section dimension at 4 mm～12 mm,the quenching qualified rate of the parts is over 99% by adopting the low temperature quenching.