16Mn鋼焊接研究

包括外文翻譯

摘   要

16Mn鋼是具有高強度、高韌性和耐腐蝕等優(yōu)良特性的低合金高強鋼，是我國低合金高強鋼中用量最多、產量最大的鋼種，廣泛用于制造橋梁、船舶、車輛、鍋爐、高壓容器、輸油輸氣管道、大型鋼結構等。鑒于16Mn鋼在我國工業(yè)和國民經濟建設中的重要性，而16Mn鋼的焊接又是16Mn鋼應用中必不可少的一道工藝技術,因此16Mn鋼的焊接進行研究對實踐應用意義重大。本課題采用焊條電弧焊對16Mn鋼進行焊接，分析焊接接頭的組織和性能的變化；并對得到的焊接接頭進行正火處理，分析熱處理前后焊接接頭組織和性能的變化。

結果表明，焊接接頭焊縫區(qū)組織為柱狀晶；熔合區(qū)為粗大晶粒；過熱區(qū)為魏氏組織；完全結晶區(qū)為細小的鐵素體和珠光體；不完全結晶區(qū)一部分為細小的鐵素體和珠光體，一部分為粗大的鐵素體。由于熔合區(qū)粗大晶粒和過熱區(qū)魏氏組織的存在使得16Mn鋼焊接接頭可能存在冷裂紋和熱影響區(qū)脆化等缺陷。所以對其進行焊后正火處理，熱處理后的焊接接頭晶粒明顯比未熱處理過的要細小，組織結構更加均勻。硬度也相應的有所升高。因此，熱處理可以改善焊接接頭的組織，并提高其性能。

本課題研究的16Mn鋼焊條電弧焊工藝、焊接接頭組織和性能以及焊后熱處理工藝可為實踐生產中16Mn鋼的焊接提供參考。

關鍵詞：16Mn鋼；焊條電弧焊；焊接接頭；組織和性能；熱處理

Welding Research of 16Mn Steel

Abstract

16Mn steel is a low alloy high strength steel which has high strength, high toughness and corrosion resistance and other excellent characteristics. It has the largest amount and the largest steel production among the low alloy high strength steel in China. It is widely used in manufacture of bridges, ships, vehicles, boilers, pressure vessels, pipelines, large steel structure. In view of the importance of 16Mn steel in ours industry and national economy, also 16Mn steel welding is an essential technology, so the welding of steel 16Mn study is significant for practical application. In this issue 16Mn steel was welded by SMAW, the changes welded joint were analyzed in the organization and performance; welded joints were obtained by normalizing processing, and analyzed the changes of the organization and performance between before and after heat treatment.

The results show that the weld zone is the columnar crystal; fusion zone is coarse crystal; hot area is the widmanstatten structure; completely crystalline region is the ferrite and pearlite; one part of incomplete crystalline region is the small Ferrite and Pearlite, another is the coarse Ferrite. The coarse crystal of the 16Mn steel welded joint fusion zone and the widmanstatten structure of the 16Mn steel welded joint hot area as the result of Cold cracking and HAZ. So it was processed by normalizing after welding, welded joints after heat treatment were significantly higher than the grain is not heat treated to small and more uniform structure. Hardness was increased accordingly. Therefore, heat treatment of welded joints can improve the organization and improve its performance. 

Research of 16Mn steel's SMAW, microstructure and properties of welded joints, heat treatment after welding can be used as a reference of the welding of 16Mn steel in practice.

Keywords: 16Mn steel; electrode arc welding; welded joint; microstructure and properties; heat treatment

目    錄

引  言 1

第1章  緒  論 2

1.1  背景與意義 2

1.2  發(fā)展概況 2

1.3  來源與內容 3

第2章  焊接理論知識 4

2.1  焊接性及其實驗評定 4

2.1.1  焊接性及影響因素 4

2.1.2  焊接性評定原則及方法 5

2.2  焊接接頭及組織和性能 7

2.2.1  焊接接頭的概念 7

2.2.2  焊接接頭的基本形式 8

2.2.3  焊接接頭的設計要求 10

2.2.4  坡口的基本形式 10

2.2.5  焊接接頭特性 11

2.3  焊條電弧焊 13

2.3.1  焊條電弧焊概述 13

2.3.2  焊接設備及輔助工具 13

2.3.3  焊條電弧焊基礎 16

2.3.4  焊條電弧焊工藝參數 18

2.3.5  焊條電弧焊的基本操作技術 19

2.3.6  常見的焊條電弧焊缺陷及防治措施 21

第3章  實驗過程 22

3.1  16Mn的焊接 22

3.1.1  16Mn鋼簡介 22

3.1.2  16Mn鋼的焊接性 23

3.1.3  16Mn鋼的焊接工藝參數 23

3.2  金相試樣的制備、觀察及其硬度測試 25

3.2.1  金相試樣的制備 25

3.2.2  金相試樣的觀察 26

3.2.3  試樣的硬度測試 26

第4章  實驗結果分析 28

4.1  焊接接頭金相組織分析 28

4.1.1  焊縫區(qū) 28

4.1.2  熔合區(qū) 28

4.1.3  過熱區(qū) 29

4.1.4  完全結晶區(qū) 29

4.1.5  不完全結晶區(qū) 30

4.1.6  母材 31

4.2  焊接接頭硬度分析 31

結論與展望 34

結論 34

展望 35

致    謝 36

參考文獻 37

附錄A 引用的英文資料及翻譯 38

附錄B 主要參考文獻及摘要 47