论文部分内容阅读
调质钢热处理规范的选择,取决于零件的服役条件。除静强度外,通常还需具备高的疲劳强度和足够高的冲击韧性,特别是低的脆性转变温度。通过各种表面处理获得高的耐磨性也常常是必要的。当进行材料和热处理工艺的最终选择时,还必须考虑材料的工艺性能。对于调质钢,淬火时力求得到马氏体组织,采用不同的回火温度和回火时间,可以在很宽的范围内改变钢的强度水平。这一强度变化范围系处于退火钢和淬火钢的强度值之间。对于每一种钢来说都存在这样的热处理温度——时间条件范围,在此范围内钢的强度和冲击韧性均可得到最佳配合,并且这一范围的位置取决于钢的含碳量。图1是根据含碳量和经标准热处理的钢的强度值,确定钢的最佳强度曲线。这些曲线是以直径<20mm的半成品根据多年的生产性试验结果建立的,钢的牌号列于表1。
Quenched and tempered steel heat treatment specifications, depending on the parts of the service conditions. In addition to the static strength, it is usually necessary to have high fatigue strength and sufficiently high impact toughness, especially low brittle transition temperature. It is also often necessary to obtain high wear resistance through various surface treatments. When the final choice of materials and heat treatment process, you must also consider the process performance of the material. For quenched and tempered steel, quenching efforts to get martensite, using different tempering temperature and tempering time, can be a wide range of changes in steel strength levels. This range of intensity changes lies between the strength values of annealed steel and hardened steel. For each steel, there is a range of heat treatment temperature-time conditions in which steel strength and impact toughness are best matched and the location of this range depends on the carbon content of the steel. Figure 1 is based on the carbon content and the standard heat-treated steel strength values to determine the best steel strength curve. These curves are based on years of productive testing of semi-finished products with diameters <20 mm. The grades of steels are given in Table 1.