耐热钢和高温合金是很宽的合金领域.在高温构件的制造过程中.焊接过程是极重要的一个工序。由于被焊接的合金所涉及的范围极广.它们的成分及焊接冶金学问题极其复杂.这些复杂性包括以下内容.

Heat resistant steel and high temperature alloy are widely used in the field of high temperature components. Because the alloy is welded to a very wide. Their composition and welding metallurgy problems are very complex. The complex includes the following contents.

O合金系统复杂:可以是铁基合金《低、中及高合金钢、各种类型不锈钢、甚含很高Cr. Ni等合金元素的铁基高温合金).也可以是以Ni或C。为基的成分十分复杂的合金系统.

The complex system can be: O alloy iron-based alloy iron-based alloy ", in low and high alloy steels, various types of stainless steel, even with high Cr. Ni alloy elements). Can also be based on Ni or C. A very complex alloy system based on components

②合金组织结构复杂:可以是铁素体或珠光体（贝氏体)组织.也可以是马氏体组织或奥氏体组织;可以是单相组织.也可以是多相混合组织;可以从凝固到室温为单相状态.也可以随温度降低而发生相转变.而且相转变产物类型、数量和形态以及性能与冷却速度相关。某些合金由于成分差异和温度经历不同可能出现各种析出相.大大影响到合金的性能。

The organization structure is complex: Alloy ferrite or pearlite (bainite) organization. Can also be martensite or austenite; can be single organization. It can also be multi phase hybrid organization; from solidification to room temperature for single-phase state. Can also occur with the decrease of temperature and phase transition. Phase transformation product type, quantity and morphology and performance and cooling speed. Because of the difference of composition and temperature, some precipitates may occur in some alloys.