precision forging SKT4 die steel forgings

precision forging SKT4 die steel forgings

(1) What is SKT4?

SKT4 is a Japanese standard steel grade and a typical general-purpose steel for cold and hot dies. The hardenability, tempering resistance, wear resistance and compression resistance of this steel are all the best among chromium-tungsten-silicon impact-resistant tool steels. However, large and medium-section steels tend to have banded carbide segregation, so their toughness is poor. The steel has the best hardenability and hardenability, so the mold has the best wear resistance and compression resistance. This steel is highly sensitive to decarburization when heated, and it is difficult to control quenching deformation.

(2) Supply status of SKT4 Annealed state

(3) Chemical composition of SKT4 Japanese standard JISG4404-1972 steel (mass fraction, %): C0.50~0.60, Si<0.35, Mn 0.60~1.00, Cr 0.7~1.0, Mo0.2~0.5, Ni 1.3~3.0.

(4) Steel grades corresponding to SKT4 in various countries Taiwan CNS standard steel grade SKT4, Germany IN No. 1.2713, DIN standard steel grade 55NiCrMoV6, Spain UNE standard steel grade F.250S, US ASTM standard steel grade 6F2, US AISI/SAE standard steel grade L6, Japan JIS standard steel grade SKT4, Japan DAIDO standard steel grade GFA, Japan Hitachi HITACHI standard steel grade DM, South Korea KS standard steel grade STT4, International Organization for Standardization ISO standard steel grade 55NiCrMoV2, France NF standard steel grade 55NiCrMoV7, Russia FOCT standard steel grade 5XHM, Sweden SIS standard steel grade 2550, UK BS standard steel grade BH224/5.

(5) Heat treatment specifications for SKT4

① Hot working specifications Initial forging temperature 1050℃, final forging temperature>850℃

② Ordinary annealing specifications Temperature 740~800℃, time 2~4h, slow cooling to about 500℃, air cooling after annealing, hardness <241HBS. ③ Quenching and tempering specifications Quenching temperature 860~900℃, tempering temperature in oil 200~250℃, hardness 53~56HRC, tempering temperature 430~470℃, hardness 40~45HRC.

(6) Application examples of SKT4

① This type of steel is used to manufacture various large and medium-sized hot forging dies.

② Suitable for making various medium and large hammer forging dies with complex shapes and heavy impact loads. ③ It is the basic material for various punching and shearing tools, precision stamping dies, and cold heading dies.

Company introduction:

Qinhuangdao Zhongwei Precision Machinery Co., Ltd. was established in 1997. It is a professional manufacturer of rough forgings engaged in manufacturing and processing automotive parts, marine gearbox accessories, and engineering machinery accessories. The company can forge copper alloy, titanium alloy, aluminum alloy, carbon steel, stainless steel, high temperature alloy and other materials. The company covers an area of ​​more than 10,000 square meters, with a standard factory building of 5,000 square meters. It has a complete set of advanced production technology and equipment from mold design, development, parts manufacturing and processing. It has multiple die forging production lines mainly based on 4000T, 2500T, 1600T, 1000T, and multiple auxiliary production lines. The annual output is 15,000 tons. It is exported to more than 20 countries and regions including Germany, the United States, the United Kingdom, France, Russia, etc.