Kunshan City, He Zhiming Mold Steel Co., Ltd.
Address: 1506 Ring Road, Kunshan (339 provincial highway and Huanqing Road intersection 200 meters north)
C53 is a new cold-work tool steel for SKD11 improvement. The technical specifications are given in Japanese Industrial Standard (JIS) G4404. It overcomes SKD11 high temperature tempering hardness and lack of toughness weaknesses, will be in the field of general and precision molds to replace SKD11.
DC53 heat treatment hardness higher than SKD11, high temperature (520-530 ℃) up to 62-63HRC high hardness after tempering, DC53 over SKD11 in terms of strength and wear resistance. Toughness is 2 times SKD11, DC53 toughness in cold work die steel is more prominent, with DC53 tools rarely crack and crack, greatly improving the service life. The residual stress after wire cutting is small, the residual stress is reduced by tempering at high temperature, and the cracks and deformation after wire cutting are suppressed. Machinability and Abrasion More than SKD11, the DC53 is superior to SKD11 in terms of machinability and abrasiveness. Using the DC53 increases the tool life and reduces the number of machining steps.
1 planted die, cold forming die, cold drawing die
2. Forming roll, punch
Precision stamping die
Wire cutting precision punching die and a variety of uses stamping die
Tool for plastic deformation of difficult-to-machine materials
Cold forging, deep drawing and rolling wire mold
High-speed blanking punch, stainless steel punch
(1) Was machinability, was grinding good.
Was machinability, were grinding than SKD11 excellent, so the longer life of processing tools, processing hours more provinces.
(2) the advantages of heat treatment
Quenching and hardening than SKD11 high, so can improve the vacuum heat treatment when the lack of hardness defects.
(3) the advantages of online cutting
By high-temperature tempering can reduce the residual stress and eliminate residual austenite, wire cutting can prevent cracking, deformation problems.
(4) The advantages of surface hardening treatment
Surface hardness after hardening than SKD11 high, so can improve mold performance.
(5) the advantages of repairing welding operations
As the preheating and post-heating temperature are lower than the SKD11, so repair welding easier.
After nitriding the workpiece surface to obtain a dense layer of hardened tissue so that the workpiece wear resistance and corrosion resistance significantly increased. 525 ℃ gas nitriding surface hardness of about 1250HV, 570 ℃ soft nitriding surface hardness of about 950HV.
DC53 die steel density
DC53 Slightly more than the average mold steel, a density of 7.9g / cm 3
DC53 die steel chemical composition
Carbon Si Si Si Mn Mn Cr Cr Mo Mo Vanadium V Phosphorus p
1.00 0.91 0.32 8.00 2.00 0.28 0.0007 DC53
DC53 die steel basic performance
DC53 is a cold-working die steel improved on the basis of SKD11 (Crl2MoV). Under conventional heat treatment conditions, the residual austenite is almost completely decomposed. Generally, cryogenic treatment can be omitted, and the toughness can be maintained under strong hardness. An experimental design
DC53 after quenching at 1040 ℃ and tempering at high temperature of 520 ~ 530 ℃, hardness HRC up to 62 ~ 63, twice the toughness Crl2MoV, is currently the most commonly used in cold work die steel, and cutting, grinding more Good, electrical processing of the metamorphic layer residual stress is small, residual austenite is very small, carbide small and evenly distributed. Due to the mold force situation is more complex, some mold parts need to have some special mechanical properties, if the standard heat treatment process often can not achieve the desired performance requirements, through the heat treatment on the hardness, toughness and wear resistance and other basic characteristics Appropriate adjustment, in order to achieve the best working condition of the mold. Quenching temperature and tempering temperature is the main heat treatment process parameters, this paper focuses on the tempering characteristics of DC53. Two experimental design
In the experiment, some changes were made to the heat treatment specification of DC53, and the quenching temperature was adjusted appropriately. The tempering temperature was 6 steps, ie 100 ℃, 200 ℃, 300 ℃, 400 ℃, 500 ℃, 600 ℃. 100 ℃ tempering selection of 101-2 oven for heating, and the rest by SX-25-12 box-type resistance furnace heating, each tempering temperature to take two samples. Hardness test using metal Rockwell hardness test, carried out at room temperature, the use of HBRVU-187.5-type Bulova optical hardness. Impact test using 10mm × 10mm × 55mm non-notched specimens, JB30B impact test machine, the impact energy of 0.3 KN.m or 0.15 KN.m. Experimental results and analysis
⒈ hardness value of each sample taken three different locations measured hardness, obtained the hardness value of each tempering temperature, the hardness of each sample, DC53 at 100 ~ 500 ℃ tempering, the hardness value changes and The hardness is slightly higher at 400 ℃ tempering temperature, the standard peak hardness after tempering is generally about 520 ℃; at 600 ℃ high temperature tempering, the hardness dropped significantly, the average HRC hardness value of only 52.4, Therefore, the tempering temperature should not be too high. ⒉ impact toughness After tempering, wear off the sample surface oxidation decarburization layer, measured at different tempering temperature of the impact value of each sample, the impact of the value of each sample, DC53 tempering at 200 ℃, the average impact Value reached 60 J / cm2 above. Tempering at 500 ℃, the impact toughness is poor, showing some high temperature temper brittleness. Temperatures above 600 ℃ tempering impact toughness, but greatly reduced hardness, reach the use requirements. The experimental results show that the overall tempering stability of DC53 is good, and the hardness and impact value have little change in a certain tempering temperature range. The toughness of tempering decreases sharply at tempering from 400 ℃ to 500 ℃, ℃ tempering, the specimen of high toughness, impact value reached 85 J / cm2, but the sharp decline in hardness. In the production, for some hardness, wear resistance is not too high and toughness requirements of the cold mold can be high temperature tempering; require a higher hardness, but also have higher toughness of the cold die, it is appropriate to adopt Low temperature of about 200 ℃ tempering. Other tempering temperature hardness and impact values can be calculated using appropriate methods (such as interpolation, function approximation, etc.) to predict, and then verified by experiments. Carbides in quenched samples showed intermittent fine banded distribution. After tempering at 200 ℃, carbides were evenly distributed, and there was almost no massive carbides in the samples, so the toughness was better. From the fracture appearance, 200 ℃ tempering fracture surface cleavage step is far less than quenched specimens, 5000 times the fracture phase in the fracture with some small and shallow dimples, showing that it has a certain degree of toughness. After tempering, the retained austenite changes more fully, carbides small and evenly distributed, so that toughness increases. in conclusion
⒈ proper adjustment of quenching temperature, DC53 at 200 ℃ tempering hardness and impact toughness are higher; at 400 ~ 500 ℃ tempering hardness higher toughness decreased significantly; high impact toughness at 600 ℃ tempering, Hardness decreased significantly. ⒉ complex shape precision die, dressing die, cold rollers and other molds should adopt low temperature tempering process, so that mold parts to obtain high hardness, high toughness, good wear resistance, high strength, which can effectively extend the life of the mold to prevent Excessive wear, deformation, cracking and other early failure phenomenon. ⒊ By the impact of the larger load of the complex mold can be low quenching high back process to get higher impact toughness to prevent mold brittle fracture phenomenon, the Japanese Industrial Standards (G4404)
Japan grade DC53 is D2 improved varieties - China grade Cr8Mo2SiV, the steel is cold work die steel (wear, impact resistance), the toughness of the steel is good. American brand seems to be called D2E.