Ming Yuan Metal Products Co., Ltd supply quality imported LD new cold work die steel LD die steel chemical performance of LD mold steel prices 

 LD new cold work die steel 

 (1) mold steel Features 7Cr7Mo2V2Si Steel Code of LD, LD1, the domestic development of new high strength and toughness of special wear Die Steel, according to their purpose and take the "cold heading" Leng, Dun and two Chinese Pinyin prefix for code the original series of steel, sub-LD1, LD2, the LD, but in practical applications LD1 best, the rest less promote the use of it is still the LD code. Maintain high toughness of the steel, its compressive strength, flexural strength, abrasion resistance compared 65Nb excellent, and recommended that the steel of JB / T 6 058 file. The steel was originally developed for the Cold Heading Die. Its carbon content is lower than the equilibrium carbon law, recommended by G.Steven steel with high hardness, good toughness; join of Cr, Mo, V elements conducive to secondary hardening, to ensure that the steel has a higher than high hardness, strength and good wear resistance; a certain amount of Si in order to strengthen the matrix to improve the tempering stability. Organization of LD steel after quenching of 1100 ℃ for fine-needle martensite + residual austenite + carbides remaining, grain size of 10.5. 1100 ℃ quenching, after tempering at 570 ℃ tempered martensite + residual carbide. The steel annealing softening is very good. 

 (2) Availability state annealed. 

 (3) The main chemical composition (wt%) C 0.70 ~ 0.80, Si 0.70 to 1.20, Mn ≤ 0.40, Cr 6.50 ~ 7.50, of Mo 2.00 ~ 2.50. 

 (4) specification processing of thermal processing temperature of 850 ~ 1120 ° C, slow sand cold. 

 (5) annealing specification annealing temperature of 860 ° C, annealed hardness 180HBS about. 

 (6) quenching and tempering specification preheat temperature of 850 ° C, quenching temperature of 1100 ~ 1150 ℃, oil cooling, tempering temperature of 530 ~ 570 ℃. Temper 2 or 3 times, each time 1 ~ 2h, hardness 57 ~ 63HRC. 

 (7) Examples of typical application of the LD steel ① bolt light dies cold heading than Cr12MoV steel to improve life for more than four times the bolt cold heading trimming die and increased life expectancy by 5.4 times than Cr12MoV steel, increased life expectancy than Cr12MoV Steel nuts Cold Heading pressure ball mold 16 times nut Cold Heading Hex punch 60Si2Mn steel and increased life expectancy of 14 times. ② bicycle bottom bracket wan cold extrusion die than W18Cr4V Steel and increased life expectancy of 8 to 10 times, wrenches cold extrusion punch increased life expectancy of four to five times than W6Mo5Cr4V2 steel hexagon socket head bolts sequence punch and increased life expectancy in the W18Cr4V Steel times, bearing circle type die and increased life expectancy of 8 to 9 times than GCr15 steel, automobile plate spring punching die than Cr12MoV steel and increased life expectancy of 6.4 times. The ③ thickness 8mm heavy expanded metal mesh red knife 2.5 times and increased life expectancy than W18Cr4V Steel. ④ spring steel retaining ring Die 9 times and increased life expectancy than Cr12 steel, stainless steel retaining ring Die Cr12 steel and increased life expectancy more than 10 times. The ⑤ thread rolling dies and increased life expectancy than Cr12MoV steel increased by 4 times 2 times, than 9CrSi steel. ⑥ Electrical silicon steel die than Cr12MoV steel to improve the life of two times. ⑦ watch shell Die the Cr12 improve life five times. The ⑧ high toughness, high wear resistance of cold work die steel, tough and wear-resistant steel, life in general than Cr12MoV increased by 4-5 times. ⑨ industry in aircraft, automobiles, bearings, standard parts, motors, electrical appliances, radios, bicycles, sewing machines, washing machines, televisions, watches, meters, water meters, chains, hardware tools and daily-use hardware such as cold forging, cold extrusion, cold red, cold and cold-formed all kinds of cold-working die, life expectancy than in of W18Cr4V, of Cr12, of W6Mo5Cr4V2, Cr12MoV, CrWMn of GCr15, 60Si2Mn and T10A steel increase by several times to several times. ⑩ applicable requirements of strength and toughness and high impact loading, cold heading, Die, particularly for cold heading die and automotive spring steel standard parts and ball punching, punch. 11 of the steel cold extrusion punch of low-temperature quenching: 1100 ~ 1150 ℃ of the conventional technology Hardening, the service life of only 03 000 to 04 000 times. Switch to 1050 ℃ × 25min salt bath heating, oil cooling, and after 200 ℃ × 2.5h tempered lath martensite + carbides dispersion, hardness of 60 ~ 61HRC, the service life of up to 20000 times. 12 steel LD has been widely used in manufacturing cold forging, blanking, cold pressing, cold-formed to withstand impact, bending stress, but also require resistance to wear all kinds of cold-working die.