Ⅰ-What is Cr12MoV Cold Working Die Steel
The Cr12MoV cold working die steel produced by Jinbaicheng belongs to the category of high wear-resistant micro deformation tool steel, which is characterized by high wear resistance, hardenability, micro deformation, high thermal stability, high bending strength, and other properties. It is second only to high-speed steel and is an important material for stamping, cold heading, and other materials. Cr12MoV die steel is a carbon molybdenum ledeburite steel with a lower carbon content than Crl2 steel. Molybdenum and vanadium are added to improve the hot working performance, impact toughness and carbide distribution of the steel. Cr12MoV die steel has a lower carbon content than Cr12 die steel. The addition of new alloy elements improves the phenomenon of uneven carbide. Moreover, molybdenum and molybdenum can reduce carbide segregation and improve hardenability. Vanadium and vanadium can refine grains and increase toughness, Therefore, Jin Baicheng’s Cr12MoV mold steel has high hardenability, with a cross-section below 400mm that can be completely quenched, and can still maintain good hardness and wear resistance at 300-400 ℃. Besides, Jinbaicheng’s Cr12MoV mold steel has better toughness than other materials of the same grade in the general market, and the possibility of volume change during quenching is greatly reduced. Therefore, its high wear resistance and good comprehensive mechanical properties make Jinbaicheng’s Cr12MoV mold steel more suitable for manufacturing various molds with large cross-section, complex shape, and withstand large impacts, as well as various cold stamping tools under heavy working conditions, such as punching dies, trimming dies, rolling dies, etc Steel plate deep drawing die, circular saw, standard tools and measuring tools, thread rolling die, etc.
Ⅱ-Application Guidance of Cr12MoV Cold Working Die Steel
① Cr12MoV can be used to make complex shapes of convex, concave, and insert blocks for punching molds with material thickness>3mm. It is recommended to have a hardness of 58~62HRC when making convex molds and 60~64HRC when making concave molds.
② For the production of punch and concave molds that require high wear resistance, it is recommended to have a hardness of 60~62HRC when making the punch and 62~64HRC when making the concave mold.
③ For the production of wear-resistant concave molds in deep drawing molds, it is recommended to have a hardness of 62~64HRC.
④ Used for producing convex molds, concave molds, and insert blocks that require high wear resistance and complex shapes in bending molds. It is recommended to have a hardness of 60-64HRC when making convex molds, and 60-64HRC when making concave molds.
⑤ For the production of cold extrusion dies and dies for aluminum parts, it is recommended to have a hardness of 60-62HRC when making the dies, and 62-64HRC when making the dies.
⑥ It is recommended to use a hardness of 62~64HRC for the convex and concave molds used for making copper cold extrusion molds.
⑦ The convex and concave molds used for steel cold extrusion molds are recommended to have a hardness of 62~64HRC.
⑧ Spring steel plates with a mass fraction of 0.65%~0.80% used for forming carbon have a hardness of 37~42HRC, providing a lifespan of up to 150000 cycles.
⑨ Spring steel plates with a mass fraction of 0.65% to 0.80% used for forming carbon have a hardness of 37-42HRC, and with additional nitriding treatment, their service life can reach 400000 times.
Ⅲ-Processing of Cr12MoV Cold Working Die Steel:
Specification for softening of cold extrusion mold: Protect and heat the mold with iron filings at a temperature of 760-780 ℃ for 10 hours, with furnace cooling and a hardness of 196HBW. Cold extrusion forming can be achieved smoothly.
Specification for ordinary isothermal spheroidizing annealing: 850-870 ℃ × 3-4 hours, cooled in the furnace to 740-760 ℃ × 4-5 hours of isothermal treatment, with air cooling hardness ≤ 241HBW, eutectic carbide grade ≤ 3, optimal isothermal temperature 740-76o ℃, and time ≥ 4-5 hours.
Specification for spheroidizing annealing: (860 ± 10) ℃ × 2-4 hours, furnace cooling at a cooling rate of 30 ℃/hour, (740 ± 10) ° C x 4-6 hours, slowly cooling to 500-600 ℃ with furnace, air cooling after discharge, hardness 207-255HBW.
General quenching and tempering specifications: quenching temperature 1000-1050 ℃, oil quenching or quenching, hardness 260HRC, tempering temperature 160-180, tempering time 2 hours, or tempering temperature 325-375 ° C, tempering 2-3 times.
Low quenching and low return quenching temperature: 950 ℃ -1040 ℃, tempering temperature is around 200 ℃, secondary tempering.
High quenching and high return quenching temperature: 1050-1100 ℃, tempering temperature is around 520 ℃, secondary tempering. The secondary hardening method used for high quenching and high recycling improves hardness, but the grains will grow.
Cryogenic treatment: Cr12MoV steel undergoes cryogenic treatment, which can precipitate highly dispersed ultrafine carbides from quenched martensite, and then these ultrafine carbides can be transformed into carbides after 200 ℃ low-temperature tempering. The martensite without cryogenic treatment only precipitates a small amount of carbide in some local areas after low temperature circumferential fire.
Jinbaicheng adopts a low-temperature chemical heat treatment method, which maintains the high hardness and wear resistance of Cr12MoV steel. Three commonly used low-temperature chemical heat treatment layers, namely ion nitriding, gas nitrocarburizing, and salt bath sulfur cyanide co nitriding, have significant impact resistance and adhesion, with salt bath sulfur cyanide co nitriding being the best.
The service life of the drawing die for Jinbaicheng’s Cr12MoV stainless steel utensils, after gas nitrocarburization treatment, reaches over 30000 pieces, which is more than 10 times longer than that of similar molds treated with conventional quenching and tempering.
Ⅳ-Professional mold steel supplier – Jinbaicheng Metal
A list of our Cold Work die Steels and hot work die steel available for order, many of which we have in stock ready for immediate shipping. Jinbaicheng has one of the largest warehouses for cold work die steel in China, can offer bars sawn to length or pre-machined plates and blocks in a very short time. Official website: www.sdjbcmetal.com Email: jinbaichengmetal@gmail.com or WhatsApp at https://wa.me/18854809715
Post time: Jul-19-2023