I have a problem: i have some sampels 4037 steel subjected to induction hardening, tempering at 240C for 4 hrs again these samples are subjeted to a thermal process at 300C for 30mts, i would like to know if the above process is meant for 12mm thick section. Wht will be the change in surface hardness of the sample from induction hardening to final thermal process, also if the section of 6mm is used what will be the difference in hardness when compared with 12mm thickness part. Thanks for your infomration.

Basker Not clear whether induction hardening done is through hardening or surface hardening . Assuming it is through hardening, tempering at 240 0 C for 4 hrs should reduce hardness around 48 HRc. Yourr second thermal process at 300 0 C for 30 minutes will bring down hardness around 42- 44 HRc. A 12 mm thick sample - induction hardened (for through hardness) - will give around 42 HRc for the cycle you are planning for tempering. i.e, temper at 240 o c for 4 hrs followed by temper at 300 oc for 30 minutes. A 6 mm sample may relatively give lower hardness around 40-42 HRC. Hardness result will depend on the carbon content in 4037 grade. Lower hardness may come if carbon content is lower. or due to induction hardenss frequency and power and method chosen for quenching. Trust this is of help to you C.V.Srinivasan Nishi Engineers Pvt Ltd India Sept 27,2005 E-mail:nishi@vsnl.com >I have a problem: i have some sampels 4037 steel subjected >to induction hardening, tempering at 240C for 4 hrs again >these samples are subjeted to a thermal process at 300C for >30mts, i would like to know if the above process is meant >for 12mm thick section. Wht will be the change in surface >hardness of the sample from induction hardening to final >thermal process, also if the section of 6mm is used what >will be the difference in hardness when compared with 12mm >thickness part. Thanks for your infomration.