热作模具钢1.2344横向冲击功的提升措施  

IMPROVING MEASURES OF THE TRANSVERSE IMPACT ENERGY OF 1.2344 HOT WORKING DIE STEEL

作　　者：梁佳 Liang Jia(Hebei ZhangXuan High-tech Technology Co.,Ltd.,Xuanhua 075100,Hebei)

机构地区：[1]河北张宣高科科技有限公司,河北宣化075100

出　　处：《河北冶金》2024年第9期69-74,共6页Hebei Metallurgy

摘　　要：针对张宣科技在高端热作模具钢生产过程中无缺口冲击功平均只有230 J,没有达到预期目标300 J以上,无法满足客户质量要求的问题,分析了冲击功偏低的原因并提出了提高冲击性能的一系列优化措施。电炉冶炼环节采用EAF+LF+VOD三联工艺降低钢中有害元素含量、O、N、H气体含量以及硫化物、氮化物和氧化物等有害非金属夹杂物数量,提高钢水纯净度,适当降低影响冲击韧性的硅元素和钒元素含量,进一步优化成分;锻造环节采用多向镦拔锻造,有效将钢锭各个方向柱状枝晶打碎,实现细化晶粒,提高材料致密性效果;热处理采用锻后水冷快速冷却和超细化混合工艺,降低因冷却不当造成的二次网状链状碳化物析出数量,稳定晶界间结合力。工艺优化效果显著,钢中晶粒尺寸更加均匀细小,带状偏析基本消失,退火态组织中碳化物分布更加均匀弥散,冲击断口韧窝数量明显增多,冲击功进一步提高,稳定在平均300 J以上。The average unnotched impact energy is around 230J currently during the production process of high-end hot work mold steel in ZhangXuan Technology,which cannot meet the expected target of 300J from customer quality requirements.By analyzing the possible reasons for the low impact energy and a series of optimization measures was taken for improving impact performance.The triple EAF+LF+VOD process is employed in the electric furnace smelting to reduce the levels of harmful elements,O,N,H gases and detrimental non-metallic inclusions such as sulfides,nitrides and oxides in steel.This enhances the purity of molten steel by appropriately decreasing silicon and vanadium content which impact toughness,while further optimizing its composition.The forging stage utilizes multi-directional upsetting forging to effectively disrupt columnar dendrites within the ingot,achieving finer grain structure and improved material density.For heat treatment,water-cooled rapid cooling and ultra-fine mixing processes are adopted post-forging to minimize secondary network chain carbide precipitation due to improper cooling and stabilize grain boundary binding force.The process optimization effect is remarkable,the grain size in the steel is more uniform and fine,the band segregation basically disappears,the carbide distribution in the annealed structure is more uniform and dispersed,the number of impact fracture dimpled significantly increases,the impact energy is further increased,and the average value is more than 300 J.

关 键 词：热作模具钢 冲击功 细化晶粒 带状偏析 碳化物 纯净度 锻造变形 

分 类 号：TG142.1[一般工业技术—材料科学与工程]