[材料加工原理.ppt

第6章 材料加工过程的化学冶金 Part 1 1 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 本章主要内容 概述 杂质污染及其危害 保护措施 冶金处理 6.1 6.2 6.3 6.4 2 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 概述 6.1 1、材料加工过程特点 2、温度和环境对加工质量的影响 3、研究化学冶金的目的和任务 3 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 1、材料加工过程特点 铸造 焊接 锻压 熔炼金属-浇注-冷却成型 熔池中熔炼金属-凝固形成焊缝 加热到可塑性变形-压力促使变形 热处理 加热到相变温度以上-冷却相变 表面改性 加热至熔化或相变点以上合金化、熔凝处理、相变硬化 材料热加工过程的共同特点--高温和环境 4 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 2、温度和环境对加工质量的影响 实践表明： 环境和温度影响材料的成分、组织及性能 影响程度与材料和环境的特性密切相关 5 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 举例1：光焊丝焊接时合金元素烧损气体含量增加 •氮含量增加27倍 •氧含量增加9倍 •冲击韧性和塑性降低 6 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 举例2：活性钛与气体的相互作用 •材料的活性：钛合金焊接时需要保护的范围比钢大 •加工温度：不同温度下钛合金对不同的环境介质表现出相异的活性 7 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. Evaluation only.