How to quenching and tempering of 4140 alloy steel

     How to quenching and tempering of 4140 alloy steel?
     The quenched and tempered of 4140 alloy steel production process: electric furnace smelting (EBT), LF refining, ingot casting, hot delivery, soaking pit, rolling, slow cooling, the surface peeled, quenching, tempering, steel straightening, cleaning inspection and turned over.
     4140 alloy steel rolling process:
     Use Rolling mill will steel ingot rolled into Φ180mm ~ Φ310mm. Since 4140 steel containing Mn and S, for the steel ingot of hot delivery use the soaking temperature 1260 ℃ in the production process, soaking time 3h, so you can make the steel ingot was burn-through, the steel rolling uniform deformation. Then the steel into the slow cooling pit slow cooling 60h, and then peeled surface treatment, and then quenched and tempered.
     4140 alloy steel quenched and tempered process:
     Before quenching, need to check whether there are cracks in the surface of the AISI 4140 steel, to prevent the quenching process since the steel surface crack lead to quenching crack.
     Steel quenching in bell-type furnace, installed furnace capacity controlled at about 20t, uniform heating to (890 ± 10) ℃, average temperature, heat preservation. Before quenching, tank filled with water and maintain a certain flow rate, water temperature is 10 ~ 40 ℃. From the baked to enter the water time is controlled within 10min. Steel was hanging out from the water every 2min, and then into the water. The quenching time a total of 30min, When leave the water, the steel surface temperature at 200 ℃. Steel after quenching, tempering as soon as possible. Tempering temperature of 580 ℃, the average temperature insulation 6 ~ 8h. After baked, in the sink fast cooling to 400 ℃, and then air cooling.
   

website： http://www.songshunsteel.com/
Original Address http://www.songshunsteel.com/news_show_27_15_39.html
Reproduced please specify. xiaoyunone110