SA738Gr.A钢热处理工艺性能

Study on heat treatment technology properties of SA738Gr.A steel

通过对用于中、低温压力容器的碳锰硅钢材料的质证分析,根据相关材料规范、相应产品的技术条件分析和文献资料设计了多组热处理试验,并对试验试样进行微观组织结构及金相分析和力学性能的检测,研究不同焊后热处理温度对SA738GR.A钢工艺性能的影响。试验结果表明,不同的热处理工艺规范对其力学性能和微观组织影响较小。根据试验结果及实际产品焊接接头试样检测结果确定了封头最佳热处理工艺方案为:热成型920℃×1 min/mm空冷+正火920℃×1.5 min/mm水淬+回火650℃×2 min/mm空冷+PWHT 550℃×6 h炉冷。使用此规范制造了18件封头,均获得了满意的效果。

By analyzing the C-Mn-Si steel used for pressure vessels at medium and low temperatures,the multiple sets of heat treatment tests are designed according to relevant material specifications,analysis of product technical conditions and literatures. And the metallographic of microstructure and test mechanical properties are analyzed,the influence of different postweld heat treatment temperatures on the technology properties of SA738 GR.A steel are studied. The results show that different heat treatment technology specifications have small influence on their mechanical properties and microstructure. According to the test results and specimen test results of practical product welded joints,the optimum heat treatment technology scheme for head is determined： N920 ℃×1 min/mm air cooling ＋N920 ℃ ×1.5 min/mm water cooling ＋T650 ℃ ×2 min/mm air cooling ＋ PWHT 550 ℃ ×6 h furnace cooling. Above specification is used in the manufacture of 18 sets of head and satisfying effect is obtained.