退火温度和冷却方式对430不锈钢显微组织与性能的影响

Influence of annealing temperature and cooling method on microstructure and properties for 430 stainless steel

采用扫描电镜、拉伸试验机、硬度计和浸泡腐蚀等手段,研究了退火温度(835~1095℃)和冷却方式(水冷和空冷)对430不锈钢显微组织和性能的影响。结果表明:在低温区退火(835~875℃)、空冷和水冷方式下,430不锈钢组织中可见沿着轧制方向分布的铁素体晶粒,以及晶界处断续分布的颗粒状(Fe,Cr)_(23)C_(6)型碳化物;在高温区退火(945~1095℃)、空冷和水冷方式下,430不锈钢组织中可见铁素体、马氏体以及数量相对更少的(Fe,Cr)_(23)C_(6)型碳化物。低温区退火试样的抗拉强度和屈服强度明显低于高温区退火试样,而断后伸长率明显大于后者;945~1045℃退火后的试样腐蚀速率较小,且水冷方式下退火试样的腐蚀速率均小于相同退火温度下空冷方式的退火试样。最终确定了430不锈钢适宜的退火温度为945℃、冷却方式为水冷,此时430不锈钢具有良好的强塑性和耐腐蚀性能。

The influences of annealing temperature(835-1095℃)and cooling method(water cooling and air cooling)on microstructure and properties for 430 stainless steel were studied by means of SEM,tensile tester,hardness tester and immersion corrosion and so on.The results show that when annealing at the low temperature(835-875℃),the ferrite grains distributed along the rolling direction and granular(Fe,Cr)_(23)C_(6) carbide intermittently distributed at the grain boundaries can be seen in 430 stainless steel structure under air cooling and water cooling modes,and when annealing at the high temperature(945-1095℃),the ferrite,martensite and relatively few(Fe,Cr)_(23)C_(6) carbide can be seen in 430 stainless steel structure under air cooling and water cooling modes.The tensile strength and yield strength of samples annealed at the low temperature are significantly lower than that of samples annealed at the high temperature,while the elongation is significantly greater than that under the latter.Moreover,the corrosion rate after annealing at 945-1045℃ is small,and the corrosion rate of the annealed samples under the water cooling mode is lower than that under the air cooling mode at the same annealing temperature.Finally,it is confirmed that the suitable annealing temperature of 430 stainless steel is 945℃,and the cooling mode is water cooling.At this time,the 430 stainless steel has good strong plasticity and corrosion resistance.