当通过冷镦工艺制造内六角圆柱形螺栓时，钢的原始结构将直接影响冷镦工艺的成型能力。冷镦工艺局部区域的塑性变形可达到60％-80％。因此，钢必须具有良好的可塑性。当钢的化学成分恒定时，金相结构是确定可塑性的关键因素。通常认为大型剥落珠光体不利于冷镦，而细球形珠光体可以显着提高钢的塑性变形能力。为了获得均匀和细球化珠光体，在中碳钢和中碳合金钢的冷镦钻前进行球化（软化）退火，以更高的强度螺栓，以便更好地满足实际生产需求。对于中碳钢线材的软化退火，加热温度主要选择保持在钢的临界点处的温暖。加热温度不能太高。否则，沿晶界沉淀三种渗碳件，导致冷镦裂。对于中型碳合金钢线材，采用等温球化退火。 After heating with AC1+ (20-30%), the furnace is cooled to a little lower than Ar1 and the temperature is about 700 degrees Celsius. After a period of time, the furnace is cooled to about 500 degrees Celsius and the air is cooled out. The metallographic structure of steel changes from coarse to fine, from flake to spherical, and the cracking rate of cold heading will be greatly reduced. The softening annealing temperature of 35 45 ML35 SWRCH35K steel is 715-735 degrees Celsius, while the spheroidizing annealing temperature of SCM435 Cr SCR435 steel is 740-770 degrees Celsius and the isothermal temperature is 680-700 degrees Celsius.
公制螺栓ASTM
公制螺栓ASTM DIN933 DIN934 ASTM A193M标准：DIN，UNC，BSW，UNF，ASTM，DIN，UNC，BSW，FEN产品名称：公制螺栓ASTM A193M ASTM A325M等级：4,8 / 8.8 / 10.9 / 12.9 ECT颜色：氧化blackening,Zinc plating, Surface treatment: HDG, PTFE coated, plain, black, galvanized, yellow zinc plated Packing: 25kg carton then pallet or according to the customer’s need. Application: Machinery industry Length: 15-200mm,customized […]
镀锌重六角螺栓A325M
六角圆柱形头螺栓，镀锌重型螺栓A325M详细信息：材料：不锈钢：SS201，SS303，SS304，SS316，SS410，SS420碳钢：4.8,6.8,8.8,10.9,12.9钛：GR1-GR5，铝，黄铜，等等。尺寸：M1.6-M39长度：最高可达300mm型：平，JIS平底锅，椭圆形，圆形，绑定，I.HD，Brier，PF。HD，按钮，填充，ANSI.PAN，PAN洗衣机，缩进的十六进制等标准：ISO，GB，DIN，[...]
