17CrNiMo6

17CrNiMo6
Recently, a 17CrNiMo6 gear after carburizing quenching test, the results are as follows:
Quenching tempering hardness: 61.5~63HRC, 158 DEG C after tempering hardness of 58.8~60HRC, 163 DEG C to tempering hardness 59~60HRC, 170 DEG C tempering 59~61HRC and 200 DEG C tempering hardness 58~62.5HRC. 158 DEG C after tempering section cut detection CHD=1.25, XC=41.5HRC. After the samples 163 DEG C to temper, CHD=1.20; section 170 DEG C to tempering after re section cut detection: XC=38~39HRC, CHD=1.20. 158 DEG C, 163 DEG C, 170 DEG C after tempering microstructure in turn upload
Pretreatment:
Forging blanks using isothermal normalizing, heated to 950 DEG C (with or without heating section?), austenitizing cooling to 650 DEG C isothermal, isothermal temperature can be adjusted by detecting blank hardness, hardness to control in 160~200HBS. also can use normalizing + tempering heat treatment (if normalization plus high temperature tempering, the normalizing temperature and tempering temperature each take and how much is appropriate??).
Carburizing: General carburizing temperature at about 930 degrees Celsius (650 degrees Celsius, 850 degrees Celsius heating insulation), 20h strong infiltration, 10h diffusion, and then cooling (air cooling or oil cold) to room temperature.
High temperature tempering: 650~680 tempering, can significantly reduce the amount of residual austenite.
Quenching: heated to 830~870 degrees C quenching (air cooling or oil cooling).
2 low temperature tempering: 170~210 C low temperature tempering.
1 Introduction
Commonly used in manufacturing small cars, tractor engine and transmission gear, instead of the carburization of heart, higher performance requirements of 12crni3 steel manufacturing, light conditions, such as oil drilling and metallurgical open pit mine of tooth and claw cone body.
Type 17CrNiMo6 0.15-0.20 silicon carbon manganese is less than 0.40 0.40-0.60
Standard JB / T 6395-2010 alloy structure steel material name
2 characteristics
Compared to 17CrNiMo6 and 17CrNiMo6NiMo, low carbon 0.03%, Cr, Ni high 1%, other little difference and strength than 17CrNiMo6NiMo at least to high 200MPa. Therefore, it is widely used in gear box, with high bending strength, contact fatigue strength, 17CrNiMo6 also has high hardness and wear resistance, the core has high hardness and toughness. Comprehensive mechanical properties is higher.
3 Mechanical Properties
The ultimate tensile strength of B (MPa):1180 ~ 1420
Yield strength s (MPa):835
The rate of elongation (%): 7
Section shrinkage (%): 30 psi
The impact toughness value of alpha kV (J/cm2): 41
4 chemical composition
Carbon (C):0.15-0.20,
Silicon (Si): less than 0.40,
Mn (Mn):0.40-0.60,
Sulfur (S): less than 0.035,
P (P) = 0.035,
Cr (Cr):1.50-1.80,
Nickel (Ni):1.40-1.70,
Molybdenum (Mo):0.25-0.35
5 Delivery Status
In the heat treatment (quenching, annealing or tempering) or heat treatment delivery, delivery status should be indicated in the contract.
Heat treatment process: quenching temperature 855 + 15; tempering: 190 + 20
6 corresponding grades
European standard: 18CrNiMo7-6
GB: 17Cr2Ni2Mo