What is the arabic word or words that translate to peace? Are they present in the Quran? How many times do they appear in the Quran?
The word for peace in Arabic is سلام = salam (as in the common greeting "asalamu alaykum" = "peace be upon you").
Actually, as-Salam is one of the 99 names of Allah (although it doesn't translate well into English):
هُوَ اللَّهُ الَّذِي لَا إِلَٰهَ إِلَّا هُوَ الْمَلِكُ الْقُدُّوسُ السَّلَامُ الْمُؤْمِنُ الْمُهَيْمِنُ الْعَزِيزُ الْجَبَّارُ الْمُتَكَبِّرُ سُبْحَانَ اللَّهِ عَمَّا يُشْرِكُونَ
He is Allah, other than whom there is no deity, the Sovereign, the Pure, the Perfection, the Bestower of Faith, the Overseer, the Exalted in Might, the Compeller, the Superior. Exalted is Allah above whatever they associate with Him. -- Qur'an 59:23 and other translations
Salam occurs multiple times in different forms in the Qur'an; some random examples are:
وَبَيْنَهُمَا حِجَابٌ وَعَلَى الْأَعْرَافِ رِجَالٌ يَعْرِفُونَ كُلًّا بِسِيمَاهُمْ وَنَادَوْا أَصْحَابَ الْجَنَّةِ أَن سَلَامٌ عَلَيْكُمْ لَمْ يَدْخُلُوهَا وَهُمْ يَطْمَعُونَ
And between them will be a partition, and on [its] elevations are men who recognize all by their mark. And they call out to the companions of Paradise, "Peace be upon you." They have not [yet] entered it, but they long intensely. -- Qur'an 7:46
وَلَقَدْ جَاءَتْ رُسُلُنَا إِبْرَاهِيمَ بِالْبُشْرَىٰ قَالُوا سَلَامًا قَالَ سَلَامٌ فَمَا لَبِثَ أَن جَاءَ بِعِجْلٍ حَنِيذٍ
And certainly did Our messengers come to Abraham with good tidings; they said, "Peace." He said, "Peace," and did not delay in bringing [them] a roasted calf. -- Qur'an 11:69
قَالَ سَلَامٌ عَلَيْكَ سَأَسْتَغْفِرُ لَكَ رَبِّي إِنَّهُ كَانَ بِي حَفِيًّا
[Abraham] said, "Peace will be upon you. I will ask forgiveness for you of my Lord. Indeed, He is ever gracious to me. -- Qur'an 19:47
إِلَّا قِيلًا سَلَامًا سَلَامًا
Only a saying: "Peace, peace." -- Qur'an 56:26
Enumeration is difficult as both English and Arabic are nuanced. Understand Islam discusses the enumeration:
Salaam comes from the root seen-laam-meem, which points to three main meanings. The first main meaning is to be peaceful, content, and tranquil. The second is to be free from imperfections, and the third main meaning is to be safe, secure, and well.
This root appears 140 times in the Quran in 16 derived forms. Examples of these forms are aslama (“submits”), salaamun (“peace”), saleemin (“sound”), al-islaami (“Islam”) and al-muslimeen (“the Muslims”).
However, there's no consistent way of defining when a word is best translated as "peace" or another word. For example "make peace" vs. "make settlement" in Qur'an 49:9. (Another example is Qur'an 13:28.)