H13钢热挤压模具热处理工艺的.doc

H13 钢热挤压模具热处理工艺设计 摘要 H13 钢以其高的淬透性、强韧性和热疲劳性能在国内外得到广泛的应用，用于制作热挤压模、铝合金压铸模、热锻模等，是当前世界范围内使用最广泛的热挤压模具钢之一。在钢的化学成分不变的情况下，热处理过程是改变他们的组织和结构的最有效的方法。而对 H13 钢模具进行表面改性处理，是综合改善模具寿命的关键。而表面渗氮是最常见的表面处理方法。渗氮的好坏直接关系到模具的使用寿命。 本文以实际生产中的 H13 钢铝型材挤压模具为研究材料,通过观察其氮化层组织，进行硬度测量等实验，分析其性能及失效原因。并通过 XRD 实验，观察衍射图谱，分析其性能。通过不同的淬火和回火方式进行热处理，并进行金相实验，观察其组织,测量其硬度，从而进行比较和分析，找到比较好的组织性能，从而确定好的热处理方法。研究结果表明：造成 H13 钢失效的主要原因为氮化组织粗大，氮化层白亮层消失。经过热处理发现H13 钢经油淬后组织最好，回火组织的变化和回火温度存在密切关系。在 350℃时回火组织为回火马氏体，回火组织形态与淬火后组织形态差别不大，均为板条状。随回火温度的升高到 450℃组织仍为回火马氏体。回火温度到 550℃左右时回火组织向回火托氏体转变，合金氮化物析出，部分碳化物聚集长大。随回火温度的升高硬度先上升后下降。 关键词：H13 钢，热处理，氮化层, 回火组织 热挤压 H13 steel with high hardenability,strength and toughness,thermal fatigue behavior is widely used in and abroad,which can be used in the manufacture of hot extrusion die,aluminium alloy die-casting die,hot forging die,etc,In nowadays,H13 steel is one of the most widely used hot die steel in worldwide. The heat treatment process is the most effective method to change the microstructure of steels while the chemical composition is invariable.And for H13 steel die surface modification treatment,is the key to comprehensively improve the die life.Surface nitriding is the most common surface preparation methods .The stand or fall of nitriding have the direct bearing on the service life of mould. Based on the actual production of aluminum extrusion dies of H13 steel as the research material.By observing the nitrided lauer, hardness measurement experiments, analysis of its performance and failure reasons.And though the XRD experiment,observed diffraction pattern,analyzes its performance. Through the different way of quenching and tempering heatment, and metallographic experiment,observe its organization, measuring its hardness, so as to compare and analysis ,find better organizational performance,good heat treatment method. Key words:H13 steel, heat treatment , nitrided layer ,tempered structure 目录 1 绪 论.................