background info

<< Click to Display Table of Contents >>

Navigation:  »No topics above this level«

background info

Below is a table with approximate values ​​of heat transfer coefficients for different quenching media and their speeds ( reference: A.S.M. Handbook Vol. 04 - Heat treatment):

Quenching medium

Quenching medium Temperature

 

Quench Velocity

Grossmann
number
[h/ 2k]

heat transfer Coefficient

°C

°F

m/s

ft/ min

W/ m2K

btu/ft2 h°F

Water

32

90

0

0

1.1

5000

880

0.25

50

2.1

9000

1600

0.51

100

2.7

12000

2100

0.76

150

2.8

12000

2100

55

130

0

0

0.2

1000

180

0.25

50

0.6

2500

440

0.51

100

1.5

6500

1100

0.76

150

2.4

10500

1850

Oil with high
hardening ability

60

140

0.00

0

0.5

2000

350

0.25

50

1.0

4500

790

0.51

100

1.1

5000

880

0.76

150

1.5

6500

1200

25% polyvinyl pyrrolidone

43

110

0

0

0.8

3500

620

0.25

50

1.3

6000

1100

0.51

100

1.5

6500

1200

0.76

150

1.8

7500

1300

Mineral oil

65

150

0.51

100

0.7

3000

530

Martempering oil

150

300

0.51

100

1.2

5000

880

Air

27

80

0

0

0.05

200

35

2.54

500

0.06

250

44

5.08

1000

0.08

350

62