CN101985683A

CN101985683A - Quenching process of Cr12MoV roller

Info

Publication number: CN101985683A
Application number: CN2010105421009A
Authority: CN
Inventors: 原春光
Original assignee: DALIAN METALLURGY TOOL PLANT Co Ltd
Current assignee: DALIAN METALLURGY TOOL PLANT Co Ltd
Priority date: 2010-11-13
Filing date: 2010-11-13
Publication date: 2011-03-16

Abstract

The invention relates to a quenching process of a Cr12MoV roller, which comprises the following steps: insulating at the quenching heating temperature of 650 DEG C for cumulative time according to the reference that a workpiece per millimeter of effective wall thickness is insulated for 2 minutes; heating to 1020 DEG C, and insulating for cumulative time according to the reference that the workpiece per millimeter of effective wall thickness is insulated for 1 minute; putting the workpiece into a 50% KNO3 and NaNo2 nitrate solution at 300 DEG C for carrying out isothermal treatment for 2 hours, and then, taking out the workpiece; and tempering the workpiece at 180 DEG C thrice for cumulative time according to the reference that the workpiece per millimeter of effective thickness is insulated for 10 minutes. By using nitrate for quenching, the hardness of the Cr12MoV roller is ensured and the wear resistance of the Cr12MoV roller in use is increased.

Description

Cr 12The quenching technology of MoV roll

Technical field

The present invention relates to a kind of thermal treatment process that material is carried out isothermal quenching, especially to Cr ₁₂The quenching technology of MoV roll.

Background technology

Domestic roll manufacturing adopts that conventional martensite is quenched, tempering heat treatment process.Because martensitic stucture is hard and crisp, in the thermal treatment heat-processed, the roller surface oxidation and decarbonization, the back of quenching forms surperficial tensile stress, transports collision at inter process the roll cracking often takes place, and grinds to add easily to form grinding crack man-hour; Secondly, roll in use, the load that withstands shocks is big, working conditions is abominable, has quite a few roll cracking and rib to rupture; Moreover the marquench workpiece deformation is big, scrap rate is high and the mill finishing allowance is big, and production causes very big waste to roll.

Summary of the invention

In view of the defective that prior art exists, the present invention has designed a kind of Cr ₁₂The quenching technology of MoV roll uses the roll after this art breading to have high toughness and long fatigue lifetime, especially works in heavy duty with under impacting, and can improve work-ing life and operating reliability.

For achieving the above object, the technology used in the present invention solution Cr ₁₂The quenching technology of MoV roll is that quenching temperature is 650 ℃, is benchmark with the workpiece effective thickness, every mm thick insulation 2 minutes, cumulative time, reheat to 1020 ℃ is a benchmark with the workpiece effective thickness, every mm thick insulation 1 minute, the cumulative time, workpiece is put into 300 ℃ 50%KNO ₃+ NaNo ₂Isothermal in the nitrate solution, isothermal time took out in 2 hours, and workpiece is 180 ℃ of tempering three times, and the time is benchmark with the workpiece net thickness, every mm thick insulation 10 minutes, cumulative time.

After adopting such scheme, compared with prior art have following beneficial effect: the present invention adopts nitrate quenching, has guaranteed Cr ₁₂The hardness of MoV roll has increased the wear resistance in using.

Description of drawings

Fig. 1 is a process schematic representation of the present invention.

Embodiment

Cr shown in Figure 1 ₁₂The quenching technology figure of MoV roll: quenching temperature is 650 ℃, with the workpiece effective thickness is benchmark, every mm thick insulation 2 minutes, cumulative time, suppose that the workpiece net thickness is 10mm, then insulation 20 minutes under 650 ℃ temperature, reheat to 1020 ℃ is a benchmark with the workpiece effective thickness, every mm thick insulation 1 minute, cumulative time then is incubated 10 minutes under 1020 ℃ temperature, workpiece is put into 300 ℃ 50%KNO ₃+ NaNo ₂Isothermal in the nitrate solution, isothermal time took out in 2 hours, and workpiece is 180 ℃ of tempering three times, and the time is benchmark with the workpiece net thickness, every mm thick insulation 10 minutes, cumulative time.Its tissue of back that quenches has very high obdurability, yield strength and fracture toughness property, and impelling strength is quenched, improved 65% after the tempering than conventional martensite.And 3 tempering have improved the cracked problem of workpiece, therefore, and through the Cr of means of isothermal quenching ₁₂MoV can improve the roll campaign and the reliability of working under shock-resistant loading capacity and the severe environmental conditions.

Claims

1.Cr ₁₂The quenching technology of MoV roll, it is characterized in that: quenching temperature is 650 ℃, with the workpiece effective thickness is benchmark, every mm thick insulation 2 minutes, cumulative time, reheat to 1020 ℃, with the workpiece effective thickness is benchmark, every mm thick insulation 1 minute, the cumulative time, workpiece is put into 300 ℃ 50%KNO ₃+ NaNo ₂Isothermal in the nitrate solution, isothermal time took out in 2 hours, and workpiece is 180 ℃ of tempering three times, and the time is benchmark with the workpiece net thickness, every mm thick insulation 10 minutes, cumulative time.