The carbon content of the steel and alloying elements are often, it's thermal conductivity is poor. If heated too quickly, is bound to cause a lot of heat stress, this may not only cause heating of the workpiece becomes open, but the quality of heat treatment is unfavorable. Therefore, high carbon steel, high alloy steel, high speed steel type of steel must be heated slowly (or define certain heating rate), sometimes even before heating to the desired temperature once or twice to warm up. Such as high speed steel hardening, preheating it twice. According to the latest market report on the well-known steel information organizations "My iron and steel" offer, last week, the domestic spot steel price index pulled back slightly to close at 111.11 points, down 0.08 percent week. Market participants observe MH51 sheet, last week and billet steel futures price linkage to rise, driven by a significant increase in confidence in the spot steel market. But by this week, futures and billet prices both correction, spot steel prices also will adjust the downstream is slowed down the speed of purchase. Isothermal annealing is mainly used to refine the organization of carbon steel, alloy steel forgings, stampings, etc., reduce the hardness to prevent white spots and even organizations. Annealing is heated to 30-50 degrees Celsius above Ac3, isothermal above Ac1 20-30 degrees Celsius, insulation can be adopted in accordance with the fully annealed. Cooling rapidly cooled to below Ac1 isotherm. Isothermal time more important: Carbon 12 hours, alloy 3-4 hours. And so the end of the warm time, remove the air cooling. Foreign anti-dumping actually not much impact on the domestic scale mass of swirling steel stage, after all the regular products such as steel production, reliable quality, reasonable price in the eyes of foreigners peers gold is still very full of MH51 wholesalers, Under the circumstances the conduct informal channels are also, not only does the anti-dumping storm blowing its body, but also the opportunity to get rid of the market in shoddy, disrupt the black sheep of the international market trading order. So basically these mills sit back, quite see Pretrial blossom, since the extra cash I chic style. Shantou increasingly large steel mold, especially in increasingly large molding parts, in order to improve production efficiency, a multi-cavity mold, so a large block of steel demand will increase year by year; precision molds increasingly high requirements for the quality of steel is good, size high accuracy, good stability; the demand for plastic mold steels, die casting mold steel is increasing; the demand for high-grade steel mold growing increasingly surplus low-grade tool steel. Yong Wei mold steel _MH51 wholesalers _ Lianjiang MH51 provided by Yong Wei steel mold. Looking for "Die steel, DC53, SKD11.SUS440C, SUS420" reliable supplier, choose to have the entire network ShangMeng Certified: Dongguan City An Yongwei mold steel shop (www.dgyongwei.com), trustworthiness and reliability, now click on "Commercial Union Support" on page live chat with us now!